diff --git a/src/color.rs b/src/color.rs
index b94b4aad..83c6ca7f 100644
--- a/src/color.rs
+++ b/src/color.rs
@@ -4,6 +4,7 @@
 
 use std::f32::consts::PI;
 use std::fmt;
+use std::str::FromStr;
 
 use super::{BasicParseError, ParseError, Parser, ToCss, Token};
 
@@ -221,7 +222,7 @@ macro_rules! impl_lab_like {
 
         #[cfg(feature = "serde")]
         impl Serialize for $cls {
-            fn serialize<S>(&self, serializer: S) -> Result<serde::ser::Ok, serde::ser::Error>
+            fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
             where
                 S: Serializer,
             {
@@ -231,7 +232,7 @@ macro_rules! impl_lab_like {
 
         #[cfg(feature = "serde")]
         impl<'de> Deserialize<'de> for $cls {
-            fn deserialize<D>(deserializer: D) -> Result<Self, serde::de::Error>
+            fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
             where
                 D: Deserializer<'de>,
             {
@@ -309,7 +310,7 @@ macro_rules! impl_lch_like {
 
         #[cfg(feature = "serde")]
         impl Serialize for $cls {
-            fn serialize<S>(&self, serializer: S) -> Result<serde::ser::Ok, serde::ser::Error>
+            fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
             where
                 S: Serializer,
             {
@@ -319,7 +320,7 @@ macro_rules! impl_lch_like {
 
         #[cfg(feature = "serde")]
         impl<'de> Deserialize<'de> for $cls {
-            fn deserialize<D>(deserializer: D) -> Result<Self, serde::de::Error>
+            fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
             where
                 D: Deserializer<'de>,
             {
@@ -350,6 +351,122 @@ macro_rules! impl_lch_like {
 impl_lch_like!(Lch, "lch");
 impl_lch_like!(Oklch, "oklch");
 
+/// A Predefined color space specified in:
+/// https://w3c.github.io/csswg-drafts/css-color-4/#predefined
+#[derive(Clone, Copy, PartialEq, Debug)]
+pub enum PredefinedColorSpace {
+    /// https://w3c.github.io/csswg-drafts/css-color-4/#predefined-sRGB
+    Srgb,
+    /// https://w3c.github.io/csswg-drafts/css-color-4/#predefined-sRGB-linear
+    SrgbLinear,
+    /// https://w3c.github.io/csswg-drafts/css-color-4/#predefined-display-p3
+    DisplayP3,
+    /// https://w3c.github.io/csswg-drafts/css-color-4/#predefined-a98-rgb
+    A98Rgb,
+    /// https://w3c.github.io/csswg-drafts/css-color-4/#predefined-prophoto-rgb
+    ProphotoRgb,
+    /// https://w3c.github.io/csswg-drafts/css-color-4/#predefined-rec2020
+    Rec2020,
+    /// https://w3c.github.io/csswg-drafts/css-color-4/#predefined-xyz
+    XyzD50,
+    /// https://w3c.github.io/csswg-drafts/css-color-4/#predefined-xyz
+    XyzD65,
+}
+
+impl PredefinedColorSpace {
+    /// Returns the string value of the predefined color space.
+    pub fn as_str(&self) -> &str {
+        match self {
+            PredefinedColorSpace::Srgb => "srgb",
+            PredefinedColorSpace::SrgbLinear => "srgb-linear",
+            PredefinedColorSpace::DisplayP3 => "display-p3",
+            PredefinedColorSpace::A98Rgb => "a98-rgb",
+            PredefinedColorSpace::ProphotoRgb => "prophoto-rgb",
+            PredefinedColorSpace::Rec2020 => "rec2020",
+            PredefinedColorSpace::XyzD50 => "xyz-d50",
+            PredefinedColorSpace::XyzD65 => "xyz-d65",
+        }
+    }
+}
+
+impl FromStr for PredefinedColorSpace {
+    type Err = ();
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(match_ignore_ascii_case! { s,
+            "srgb" => PredefinedColorSpace::Srgb,
+            "srgb-linear" => PredefinedColorSpace::SrgbLinear,
+            "display-p3" => PredefinedColorSpace::DisplayP3,
+            "a98-rgb" => PredefinedColorSpace::A98Rgb,
+            "prophoto-rgb" => PredefinedColorSpace::ProphotoRgb,
+            "rec2020" => PredefinedColorSpace::Rec2020,
+            "xyz-d50" => PredefinedColorSpace::XyzD50,
+            "xyz" | "xyz-d65" => PredefinedColorSpace::XyzD65,
+
+            _ => return Err(()),
+        })
+    }
+}
+
+impl ToCss for PredefinedColorSpace {
+    fn to_css<W>(&self, dest: &mut W) -> fmt::Result
+    where
+        W: fmt::Write,
+    {
+        dest.write_str(self.as_str())
+    }
+}
+
+/// A color specified by the color() function.
+/// https://w3c.github.io/csswg-drafts/css-color-4/#color-function
+#[derive(Clone, Copy, PartialEq, Debug)]
+pub struct ColorFunction {
+    /// The color space for this color.
+    pub color_space: PredefinedColorSpace,
+    /// The first component of the color.  Either red or x.
+    pub c1: f32,
+    /// The second component of the color.  Either green or y.
+    pub c2: f32,
+    /// The third component of the color.  Either blue or z.
+    pub c3: f32,
+    /// The alpha component of the color.
+    pub alpha: f32,
+}
+
+impl ColorFunction {
+    /// Construct a new color function definition with the given color space and
+    /// color components.
+    pub fn new(color_space: PredefinedColorSpace, c1: f32, c2: f32, c3: f32, alpha: f32) -> Self {
+        Self {
+            color_space,
+            c1,
+            c2,
+            c3,
+            alpha,
+        }
+    }
+}
+
+impl ToCss for ColorFunction {
+    fn to_css<W>(&self, dest: &mut W) -> fmt::Result
+    where
+        W: fmt::Write,
+    {
+        dest.write_str("color(")?;
+        self.color_space.to_css(dest)?;
+        dest.write_char(' ')?;
+        self.c1.to_css(dest)?;
+        dest.write_char(' ')?;
+        self.c2.to_css(dest)?;
+        dest.write_char(' ')?;
+        self.c3.to_css(dest)?;
+
+        serialize_alpha(dest, self.alpha, false)?;
+
+        dest.write_char(')')
+    }
+}
+
 /// An absolutely specified color.
 /// https://w3c.github.io/csswg-drafts/css-color-4/#typedef-absolute-color-base
 #[derive(Clone, Copy, PartialEq, Debug)]
@@ -370,6 +487,8 @@ pub enum AbsoluteColor {
     /// Specifies an Oklab color by Oklab Lightness, Chroma, and hue using
     /// the OKLCH cylindrical coordinate model.
     Oklch(Oklch),
+    /// Specifies a color in a predefined color space.
+    ColorFunction(ColorFunction),
 }
 
 impl AbsoluteColor {
@@ -381,6 +500,7 @@ impl AbsoluteColor {
             Self::Lch(c) => c.alpha,
             Self::Oklab(c) => c.alpha,
             Self::Oklch(c) => c.alpha,
+            Self::ColorFunction(c) => c.alpha,
         }
     }
 }
@@ -396,6 +516,7 @@ impl ToCss for AbsoluteColor {
             Self::Lch(lch) => lch.to_css(dest),
             Self::Oklab(lab) => lab.to_css(dest),
             Self::Oklch(lch) => lch.to_css(dest),
+            Self::ColorFunction(color_function) => color_function.to_css(dest),
         }
     }
 }
@@ -571,7 +692,7 @@ impl Color {
             Token::Function(ref name) => {
                 let name = name.clone();
                 return input.parse_nested_block(|arguments| {
-                    parse_color_function(component_parser, &*name, arguments)
+                    parse_color(component_parser, &*name, arguments)
                 });
             }
             _ => Err(()),
@@ -785,7 +906,7 @@ fn clamp_floor_256_f32(val: f32) -> u8 {
 }
 
 #[inline]
-fn parse_color_function<'i, 't, ComponentParser>(
+fn parse_color<'i, 't, ComponentParser>(
     component_parser: &ComponentParser,
     name: &str,
     arguments: &mut Parser<'i, 't>,
@@ -827,6 +948,8 @@ where
             Color::Absolute(AbsoluteColor::Oklch(Oklch::new(l.max(0.), c.max(0.), h, alpha)))
         }),
 
+        "color" => parse_color_function(component_parser, arguments),
+
         _ => return Err(arguments.new_unexpected_token_error(Token::Ident(name.to_owned().into()))),
     }?;
 
@@ -1072,3 +1195,44 @@ where
 
     Ok(into_color(lightness, chroma, hue, alpha))
 }
+
+#[inline]
+fn parse_color_function<'i, 't, ComponentParser>(
+    component_parser: &ComponentParser,
+    arguments: &mut Parser<'i, 't>,
+) -> Result<Color, ParseError<'i, ComponentParser::Error>>
+where
+    ComponentParser: ColorComponentParser<'i>,
+{
+    let color_space = {
+        let location = arguments.current_source_location();
+
+        let ident = arguments.expect_ident()?;
+        PredefinedColorSpace::from_str(ident)
+            .map_err(|_| location.new_unexpected_token_error(Token::Ident(ident.clone())))?
+    };
+
+    macro_rules! parse_component {
+        () => {{
+            component_parser
+                .parse_number_or_percentage(arguments)?
+                .unit_value()
+        }};
+    }
+
+    let c1 = parse_component!();
+    let c2 = parse_component!();
+    let c3 = parse_component!();
+
+    let alpha = parse_alpha(component_parser, arguments, false)?;
+
+    Ok(Color::Absolute(AbsoluteColor::ColorFunction(
+        ColorFunction {
+            color_space,
+            c1,
+            c2,
+            c3,
+            alpha,
+        },
+    )))
+}
diff --git a/src/css-parsing-tests/color4_color_function.json b/src/css-parsing-tests/color4_color_function.json
new file mode 100644
index 00000000..a653c653
--- /dev/null
+++ b/src/css-parsing-tests/color4_color_function.json
@@ -0,0 +1,182 @@
+[
+  "color(srgb 0% 0% 0%)", "color(srgb 0 0 0)",
+  "color(srgb 10% 10% 10%)", "color(srgb 0.1 0.1 0.1)",
+  "color(srgb .2 .2 25%)", "color(srgb 0.2 0.2 0.25)",
+  "color(srgb 0 0 0 / 1)", "color(srgb 0 0 0)",
+  "color(srgb 0% 0 0 / 0.5)", "color(srgb 0 0 0 / 0.5)",
+  "color(srgb 20% 0 10/0.5)", "color(srgb 0.2 0 10 / 0.5)",
+  "color(srgb 20% 0 10/50%)", "color(srgb 0.2 0 10 / 0.5)",
+  "color(srgb 400% 0 10/50%)", "color(srgb 4 0 10 / 0.5)",
+  "color(srgb 50% -160 160)", "color(srgb 0.5 -160 160)",
+  "color(srgb 50% -200 200)", "color(srgb 0.5 -200 200)",
+  "color(srgb 0 0 0 / -10%)", "color(srgb 0 0 0 / 0)",
+  "color(srgb 0 0 0 / 110%)", "color(srgb 0 0 0)",
+  "color(srgb 0 0 0 / 300%)", "color(srgb 0 0 0)",
+  "color(srgb 200 200 200)", "color(srgb 200 200 200)",
+  "color(srgb 200 200 200 / 200)", "color(srgb 200 200 200)",
+  "color(srgb -200 -200 -200)", "color(srgb -200 -200 -200)",
+  "color(srgb -200 -200 -200 / -200)", "color(srgb -200 -200 -200 / 0)",
+  "color(srgb 200% 200% 200%)", "color(srgb 2 2 2)",
+  "color(srgb 200% 200% 200% / 200%)", "color(srgb 2 2 2)",
+  "color(srgb -200% -200% -200% / -200%)", "color(srgb -2 -2 -2 / 0)",
+  "color(srgb-linear 0% 0% 0%)", "color(srgb-linear 0 0 0)",
+  "color(srgb-linear 10% 10% 10%)", "color(srgb-linear 0.1 0.1 0.1)",
+  "color(srgb-linear .2 .2 25%)", "color(srgb-linear 0.2 0.2 0.25)",
+  "color(srgb-linear 0 0 0 / 1)", "color(srgb-linear 0 0 0)",
+  "color(srgb-linear 0% 0 0 / 0.5)", "color(srgb-linear 0 0 0 / 0.5)",
+  "color(srgb-linear 20% 0 10/0.5)", "color(srgb-linear 0.2 0 10 / 0.5)",
+  "color(srgb-linear 20% 0 10/50%)", "color(srgb-linear 0.2 0 10 / 0.5)",
+  "color(srgb-linear 400% 0 10/50%)", "color(srgb-linear 4 0 10 / 0.5)",
+  "color(srgb-linear 50% -160 160)", "color(srgb-linear 0.5 -160 160)",
+  "color(srgb-linear 50% -200 200)", "color(srgb-linear 0.5 -200 200)",
+  "color(srgb-linear 0 0 0 / -10%)", "color(srgb-linear 0 0 0 / 0)",
+  "color(srgb-linear 0 0 0 / 110%)", "color(srgb-linear 0 0 0)",
+  "color(srgb-linear 0 0 0 / 300%)", "color(srgb-linear 0 0 0)",
+  "color(srgb-linear 200 200 200)", "color(srgb-linear 200 200 200)",
+  "color(srgb-linear 200 200 200 / 200)", "color(srgb-linear 200 200 200)",
+  "color(srgb-linear -200 -200 -200)", "color(srgb-linear -200 -200 -200)",
+  "color(srgb-linear -200 -200 -200 / -200)", "color(srgb-linear -200 -200 -200 / 0)",
+  "color(srgb-linear 200% 200% 200%)", "color(srgb-linear 2 2 2)",
+  "color(srgb-linear 200% 200% 200% / 200%)", "color(srgb-linear 2 2 2)",
+  "color(srgb-linear -200% -200% -200% / -200%)", "color(srgb-linear -2 -2 -2 / 0)",
+  "color(display-p3 0% 0% 0%)", "color(display-p3 0 0 0)",
+  "color(display-p3 10% 10% 10%)", "color(display-p3 0.1 0.1 0.1)",
+  "color(display-p3 .2 .2 25%)", "color(display-p3 0.2 0.2 0.25)",
+  "color(display-p3 0 0 0 / 1)", "color(display-p3 0 0 0)",
+  "color(display-p3 0% 0 0 / 0.5)", "color(display-p3 0 0 0 / 0.5)",
+  "color(display-p3 20% 0 10/0.5)", "color(display-p3 0.2 0 10 / 0.5)",
+  "color(display-p3 20% 0 10/50%)", "color(display-p3 0.2 0 10 / 0.5)",
+  "color(display-p3 400% 0 10/50%)", "color(display-p3 4 0 10 / 0.5)",
+  "color(display-p3 50% -160 160)", "color(display-p3 0.5 -160 160)",
+  "color(display-p3 50% -200 200)", "color(display-p3 0.5 -200 200)",
+  "color(display-p3 0 0 0 / -10%)", "color(display-p3 0 0 0 / 0)",
+  "color(display-p3 0 0 0 / 110%)", "color(display-p3 0 0 0)",
+  "color(display-p3 0 0 0 / 300%)", "color(display-p3 0 0 0)",
+  "color(display-p3 200 200 200)", "color(display-p3 200 200 200)",
+  "color(display-p3 200 200 200 / 200)", "color(display-p3 200 200 200)",
+  "color(display-p3 -200 -200 -200)", "color(display-p3 -200 -200 -200)",
+  "color(display-p3 -200 -200 -200 / -200)", "color(display-p3 -200 -200 -200 / 0)",
+  "color(display-p3 200% 200% 200%)", "color(display-p3 2 2 2)",
+  "color(display-p3 200% 200% 200% / 200%)", "color(display-p3 2 2 2)",
+  "color(display-p3 -200% -200% -200% / -200%)", "color(display-p3 -2 -2 -2 / 0)",
+  "color(a98-rgb 0% 0% 0%)", "color(a98-rgb 0 0 0)",
+  "color(a98-rgb 10% 10% 10%)", "color(a98-rgb 0.1 0.1 0.1)",
+  "color(a98-rgb .2 .2 25%)", "color(a98-rgb 0.2 0.2 0.25)",
+  "color(a98-rgb 0 0 0 / 1)", "color(a98-rgb 0 0 0)",
+  "color(a98-rgb 0% 0 0 / 0.5)", "color(a98-rgb 0 0 0 / 0.5)",
+  "color(a98-rgb 20% 0 10/0.5)", "color(a98-rgb 0.2 0 10 / 0.5)",
+  "color(a98-rgb 20% 0 10/50%)", "color(a98-rgb 0.2 0 10 / 0.5)",
+  "color(a98-rgb 400% 0 10/50%)", "color(a98-rgb 4 0 10 / 0.5)",
+  "color(a98-rgb 50% -160 160)", "color(a98-rgb 0.5 -160 160)",
+  "color(a98-rgb 50% -200 200)", "color(a98-rgb 0.5 -200 200)",
+  "color(a98-rgb 0 0 0 / -10%)", "color(a98-rgb 0 0 0 / 0)",
+  "color(a98-rgb 0 0 0 / 110%)", "color(a98-rgb 0 0 0)",
+  "color(a98-rgb 0 0 0 / 300%)", "color(a98-rgb 0 0 0)",
+  "color(a98-rgb 200 200 200)", "color(a98-rgb 200 200 200)",
+  "color(a98-rgb 200 200 200 / 200)", "color(a98-rgb 200 200 200)",
+  "color(a98-rgb -200 -200 -200)", "color(a98-rgb -200 -200 -200)",
+  "color(a98-rgb -200 -200 -200 / -200)", "color(a98-rgb -200 -200 -200 / 0)",
+  "color(a98-rgb 200% 200% 200%)", "color(a98-rgb 2 2 2)",
+  "color(a98-rgb 200% 200% 200% / 200%)", "color(a98-rgb 2 2 2)",
+  "color(a98-rgb -200% -200% -200% / -200%)", "color(a98-rgb -2 -2 -2 / 0)",
+  "color(prophoto-rgb 0% 0% 0%)", "color(prophoto-rgb 0 0 0)",
+  "color(prophoto-rgb 10% 10% 10%)", "color(prophoto-rgb 0.1 0.1 0.1)",
+  "color(prophoto-rgb .2 .2 25%)", "color(prophoto-rgb 0.2 0.2 0.25)",
+  "color(prophoto-rgb 0 0 0 / 1)", "color(prophoto-rgb 0 0 0)",
+  "color(prophoto-rgb 0% 0 0 / 0.5)", "color(prophoto-rgb 0 0 0 / 0.5)",
+  "color(prophoto-rgb 20% 0 10/0.5)", "color(prophoto-rgb 0.2 0 10 / 0.5)",
+  "color(prophoto-rgb 20% 0 10/50%)", "color(prophoto-rgb 0.2 0 10 / 0.5)",
+  "color(prophoto-rgb 400% 0 10/50%)", "color(prophoto-rgb 4 0 10 / 0.5)",
+  "color(prophoto-rgb 50% -160 160)", "color(prophoto-rgb 0.5 -160 160)",
+  "color(prophoto-rgb 50% -200 200)", "color(prophoto-rgb 0.5 -200 200)",
+  "color(prophoto-rgb 0 0 0 / -10%)", "color(prophoto-rgb 0 0 0 / 0)",
+  "color(prophoto-rgb 0 0 0 / 110%)", "color(prophoto-rgb 0 0 0)",
+  "color(prophoto-rgb 0 0 0 / 300%)", "color(prophoto-rgb 0 0 0)",
+  "color(prophoto-rgb 200 200 200)", "color(prophoto-rgb 200 200 200)",
+  "color(prophoto-rgb 200 200 200 / 200)", "color(prophoto-rgb 200 200 200)",
+  "color(prophoto-rgb -200 -200 -200)", "color(prophoto-rgb -200 -200 -200)",
+  "color(prophoto-rgb -200 -200 -200 / -200)", "color(prophoto-rgb -200 -200 -200 / 0)",
+  "color(prophoto-rgb 200% 200% 200%)", "color(prophoto-rgb 2 2 2)",
+  "color(prophoto-rgb 200% 200% 200% / 200%)", "color(prophoto-rgb 2 2 2)",
+  "color(prophoto-rgb -200% -200% -200% / -200%)", "color(prophoto-rgb -2 -2 -2 / 0)",
+  "color(rec2020 0% 0% 0%)", "color(rec2020 0 0 0)",
+  "color(rec2020 10% 10% 10%)", "color(rec2020 0.1 0.1 0.1)",
+  "color(rec2020 .2 .2 25%)", "color(rec2020 0.2 0.2 0.25)",
+  "color(rec2020 0 0 0 / 1)", "color(rec2020 0 0 0)",
+  "color(rec2020 0% 0 0 / 0.5)", "color(rec2020 0 0 0 / 0.5)",
+  "color(rec2020 20% 0 10/0.5)", "color(rec2020 0.2 0 10 / 0.5)",
+  "color(rec2020 20% 0 10/50%)", "color(rec2020 0.2 0 10 / 0.5)",
+  "color(rec2020 400% 0 10/50%)", "color(rec2020 4 0 10 / 0.5)",
+  "color(rec2020 50% -160 160)", "color(rec2020 0.5 -160 160)",
+  "color(rec2020 50% -200 200)", "color(rec2020 0.5 -200 200)",
+  "color(rec2020 0 0 0 / -10%)", "color(rec2020 0 0 0 / 0)",
+  "color(rec2020 0 0 0 / 110%)", "color(rec2020 0 0 0)",
+  "color(rec2020 0 0 0 / 300%)", "color(rec2020 0 0 0)",
+  "color(rec2020 200 200 200)", "color(rec2020 200 200 200)",
+  "color(rec2020 200 200 200 / 200)", "color(rec2020 200 200 200)",
+  "color(rec2020 -200 -200 -200)", "color(rec2020 -200 -200 -200)",
+  "color(rec2020 -200 -200 -200 / -200)", "color(rec2020 -200 -200 -200 / 0)",
+  "color(rec2020 200% 200% 200%)", "color(rec2020 2 2 2)",
+  "color(rec2020 200% 200% 200% / 200%)", "color(rec2020 2 2 2)",
+  "color(rec2020 -200% -200% -200% / -200%)", "color(rec2020 -2 -2 -2 / 0)",
+  "color(xyz 0% 0% 0%)", "color(xyz-d65 0 0 0)",
+  "color(xyz 10% 10% 10%)", "color(xyz-d65 0.1 0.1 0.1)",
+  "color(xyz .2 .2 25%)", "color(xyz-d65 0.2 0.2 0.25)",
+  "color(xyz 0 0 0 / 1)", "color(xyz-d65 0 0 0)",
+  "color(xyz 0% 0 0 / 0.5)", "color(xyz-d65 0 0 0 / 0.5)",
+  "color(xyz 20% 0 10/0.5)", "color(xyz-d65 0.2 0 10 / 0.5)",
+  "color(xyz 20% 0 10/50%)", "color(xyz-d65 0.2 0 10 / 0.5)",
+  "color(xyz 400% 0 10/50%)", "color(xyz-d65 4 0 10 / 0.5)",
+  "color(xyz 50% -160 160)", "color(xyz-d65 0.5 -160 160)",
+  "color(xyz 50% -200 200)", "color(xyz-d65 0.5 -200 200)",
+  "color(xyz 0 0 0 / -10%)", "color(xyz-d65 0 0 0 / 0)",
+  "color(xyz 0 0 0 / 110%)", "color(xyz-d65 0 0 0)",
+  "color(xyz 0 0 0 / 300%)", "color(xyz-d65 0 0 0)",
+  "color(xyz 200 200 200)", "color(xyz-d65 200 200 200)",
+  "color(xyz 200 200 200 / 200)", "color(xyz-d65 200 200 200)",
+  "color(xyz -200 -200 -200)", "color(xyz-d65 -200 -200 -200)",
+  "color(xyz -200 -200 -200 / -200)", "color(xyz-d65 -200 -200 -200 / 0)",
+  "color(xyz 200% 200% 200%)", "color(xyz-d65 2 2 2)",
+  "color(xyz 200% 200% 200% / 200%)", "color(xyz-d65 2 2 2)",
+  "color(xyz -200% -200% -200% / -200%)", "color(xyz-d65 -2 -2 -2 / 0)",
+  "color(xyz-d50 0% 0% 0%)", "color(xyz-d50 0 0 0)",
+  "color(xyz-d50 10% 10% 10%)", "color(xyz-d50 0.1 0.1 0.1)",
+  "color(xyz-d50 .2 .2 25%)", "color(xyz-d50 0.2 0.2 0.25)",
+  "color(xyz-d50 0 0 0 / 1)", "color(xyz-d50 0 0 0)",
+  "color(xyz-d50 0% 0 0 / 0.5)", "color(xyz-d50 0 0 0 / 0.5)",
+  "color(xyz-d50 20% 0 10/0.5)", "color(xyz-d50 0.2 0 10 / 0.5)",
+  "color(xyz-d50 20% 0 10/50%)", "color(xyz-d50 0.2 0 10 / 0.5)",
+  "color(xyz-d50 400% 0 10/50%)", "color(xyz-d50 4 0 10 / 0.5)",
+  "color(xyz-d50 50% -160 160)", "color(xyz-d50 0.5 -160 160)",
+  "color(xyz-d50 50% -200 200)", "color(xyz-d50 0.5 -200 200)",
+  "color(xyz-d50 0 0 0 / -10%)", "color(xyz-d50 0 0 0 / 0)",
+  "color(xyz-d50 0 0 0 / 110%)", "color(xyz-d50 0 0 0)",
+  "color(xyz-d50 0 0 0 / 300%)", "color(xyz-d50 0 0 0)",
+  "color(xyz-d50 200 200 200)", "color(xyz-d50 200 200 200)",
+  "color(xyz-d50 200 200 200 / 200)", "color(xyz-d50 200 200 200)",
+  "color(xyz-d50 -200 -200 -200)", "color(xyz-d50 -200 -200 -200)",
+  "color(xyz-d50 -200 -200 -200 / -200)", "color(xyz-d50 -200 -200 -200 / 0)",
+  "color(xyz-d50 200% 200% 200%)", "color(xyz-d50 2 2 2)",
+  "color(xyz-d50 200% 200% 200% / 200%)", "color(xyz-d50 2 2 2)",
+  "color(xyz-d50 -200% -200% -200% / -200%)", "color(xyz-d50 -2 -2 -2 / 0)",
+  "color(xyz-d65 0% 0% 0%)", "color(xyz-d65 0 0 0)",
+  "color(xyz-d65 10% 10% 10%)", "color(xyz-d65 0.1 0.1 0.1)",
+  "color(xyz-d65 .2 .2 25%)", "color(xyz-d65 0.2 0.2 0.25)",
+  "color(xyz-d65 0 0 0 / 1)", "color(xyz-d65 0 0 0)",
+  "color(xyz-d65 0% 0 0 / 0.5)", "color(xyz-d65 0 0 0 / 0.5)",
+  "color(xyz-d65 20% 0 10/0.5)", "color(xyz-d65 0.2 0 10 / 0.5)",
+  "color(xyz-d65 20% 0 10/50%)", "color(xyz-d65 0.2 0 10 / 0.5)",
+  "color(xyz-d65 400% 0 10/50%)", "color(xyz-d65 4 0 10 / 0.5)",
+  "color(xyz-d65 50% -160 160)", "color(xyz-d65 0.5 -160 160)",
+  "color(xyz-d65 50% -200 200)", "color(xyz-d65 0.5 -200 200)",
+  "color(xyz-d65 0 0 0 / -10%)", "color(xyz-d65 0 0 0 / 0)",
+  "color(xyz-d65 0 0 0 / 110%)", "color(xyz-d65 0 0 0)",
+  "color(xyz-d65 0 0 0 / 300%)", "color(xyz-d65 0 0 0)",
+  "color(xyz-d65 200 200 200)", "color(xyz-d65 200 200 200)",
+  "color(xyz-d65 200 200 200 / 200)", "color(xyz-d65 200 200 200)",
+  "color(xyz-d65 -200 -200 -200)", "color(xyz-d65 -200 -200 -200)",
+  "color(xyz-d65 -200 -200 -200 / -200)", "color(xyz-d65 -200 -200 -200 / 0)",
+  "color(xyz-d65 200% 200% 200%)", "color(xyz-d65 2 2 2)",
+  "color(xyz-d65 200% 200% 200% / 200%)", "color(xyz-d65 2 2 2)",
+  "color(xyz-d65 -200% -200% -200% / -200%)", "color(xyz-d65 -2 -2 -2 / 0)"
+]
diff --git a/src/css-parsing-tests/make_color4_color_function.py b/src/css-parsing-tests/make_color4_color_function.py
new file mode 100644
index 00000000..28df857c
--- /dev/null
+++ b/src/css-parsing-tests/make_color4_color_function.py
@@ -0,0 +1,52 @@
+COLOR_SPACES = [
+    'srgb',
+    'srgb-linear',
+    'display-p3',
+    'a98-rgb',
+    'prophoto-rgb',
+    'rec2020',
+    'xyz',
+    'xyz-d50',
+    'xyz-d65'
+]
+PERMUTATIONS = [
+    ('0% 0% 0%', '0 0 0'),
+    ('10% 10% 10%', '0.1 0.1 0.1'),
+    ('.2 .2 25%', '0.2 0.2 0.25'),
+    ('0 0 0 / 1', '0 0 0'),
+    ('0% 0 0 / 0.5', '0 0 0 / 0.5'),
+    ('20% 0 10/0.5', '0.2 0 10 / 0.5'),
+    ('20% 0 10/50%', '0.2 0 10 / 0.5'),
+    ('400% 0 10/50%', '4 0 10 / 0.5'),
+    ('50% -160 160', '0.5 -160 160'),
+    ('50% -200 200', '0.5 -200 200'),
+    ('0 0 0 / -10%', '0 0 0 / 0'),
+    ('0 0 0 / 110%', '0 0 0'),
+    ('0 0 0 / 300%', '0 0 0'),
+    ('200 200 200', '200 200 200'),
+    ('200 200 200 / 200', '200 200 200'),
+    ('-200 -200 -200', '-200 -200 -200'),
+    ('-200 -200 -200 / -200', '-200 -200 -200 / 0'),
+    ('200% 200% 200%', '2 2 2'),
+    ('200% 200% 200% / 200%', '2 2 2'),
+    ('-200% -200% -200% / -200%', '-2 -2 -2 / 0'),
+]
+
+
+def result_color_space(color_space):
+    if color_space == 'xyz':
+        return 'xyz-d65'
+    else:
+        return color_space
+
+
+lines = []
+for color_space in COLOR_SPACES:
+    for permutation in PERMUTATIONS:
+        lines.append('  "color({} {})", "color({} {})"'.format(
+            color_space, permutation[0], result_color_space(color_space), permutation[1]))
+
+
+print("[")
+print(',\n'.join(lines))
+print("]")
diff --git a/src/lib.rs b/src/lib.rs
index 510c2fe6..fb96c4e4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -69,7 +69,8 @@ fn parse_border_spacing(_context: &ParserContext, input: &mut Parser)
 
 pub use crate::color::{
     hsl_to_rgb, hwb_to_rgb, parse_color_keyword, AbsoluteColor, AngleOrNumber, Color,
-    ColorComponentParser, Lab, Lch, NumberOrPercentage, Oklab, Oklch, RGBA,
+    ColorComponentParser, ColorFunction, Lab, Lch, NumberOrPercentage, Oklab, Oklch,
+    PredefinedColorSpace, RGBA,
 };
 pub use crate::cow_rc_str::CowRcStr;
 pub use crate::from_bytes::{stylesheet_encoding, EncodingSupport};
diff --git a/src/tests.rs b/src/tests.rs
index b4d25626..c1437216 100644
--- a/src/tests.rs
+++ b/src/tests.rs
@@ -404,6 +404,33 @@ fn color4_lab_lch_oklab_oklch() {
     )
 }
 
+#[test]
+fn color4_color_function() {
+    run_color_tests(
+        include_str!("css-parsing-tests/color4_color_function.json"),
+        |c| {
+            c.ok()
+                .map(|v| v.to_css_string().to_json())
+                .unwrap_or(Value::Null)
+        },
+    )
+}
+
+macro_rules! parse_single_color {
+    ($i:expr) => {{
+        let input = $i;
+        let mut input = ParserInput::new(input);
+        let mut input = Parser::new(&mut input);
+        Color::parse(&mut input).map_err(Into::<ParseError<()>>::into)
+    }};
+}
+
+#[test]
+fn color4_invalid_color_space() {
+    let result = parse_single_color!("color(invalid 1 1 1)");
+    assert!(result.is_err());
+}
+
 #[test]
 fn nth() {
     run_json_tests(include_str!("css-parsing-tests/An+B.json"), |input| {
@@ -866,6 +893,9 @@ impl ToJson for Color {
                 AbsoluteColor::Lch(ref c) => json!([c.lightness, c.chroma, c.hue, c.alpha]),
                 AbsoluteColor::Oklab(ref c) => json!([c.lightness, c.a, c.b, c.alpha]),
                 AbsoluteColor::Oklch(ref c) => json!([c.lightness, c.chroma, c.hue, c.alpha]),
+                AbsoluteColor::ColorFunction(ref c) => {
+                    json!([c.color_space.as_str(), c.c1, c.c2, c.c3, c.alpha])
+                }
             },
         }
     }