diff --git a/adafruit_pypixelbuf.py b/adafruit_pypixelbuf.py
index 799af2a..fc6fd25 100644
--- a/adafruit_pypixelbuf.py
+++ b/adafruit_pypixelbuf.py
@@ -243,6 +243,7 @@ def _parse_color(self, value):
                 r, g, b, w = value
         elif len(value) == 3 and self._dotstar_mode:
             r, g, b = value
+            w = 1.0
 
         if self._bpp == 4 and self._dotstar_mode:
             # LED startframe is three "1" bits, followed by 5 brightness bits