bug(material/theming): get-contrast-color-from-palette doesn't work with pre-defined hue names

[X-Celcius]

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

No response

Description

Using get-contrast-color-from-palette is convenient and explicit as it gives you the contrast color without having to add -contrast to the hue value. It seems to me as the right thing to choose, even though the theming documentation currently doesn't mention this function.

However the behavior can be confusing because hues such as default, lighter or darker are added only to the outer map, not the inner contrast map, when calling define-palette. Therefore you can only use it with hues that are defined in the contrast-palette from the beginning (such as 500).

There is an easy workaround but I also think that it should be fairly easy to add default, lighter, darker etc. to the inner contrast map in mat.define-palette.

Reproduction

StackBlitz link: https://stackblitz.com/edit/components-issue-egs21k?file=src%2Fstyles.scss
Steps to reproduce:

1. Use mat.get-contrast-color-from-palette with a pre-defined hue value such as default or lighter

Expected Behavior

I expect mat.get-contrast-color-from-palette($palette, default) to return the same color as mat-get-color-from-palette($palette, default-contrast) after defining a palette using mat.define-palette.

Actual Behavior

mat.get-contrast-color-from-palette looks for a hue called default in the inner contrast map but that doesn't get added to the inner contrast map when calling mat.define-palette.

Environment

• Angular: 16.2.6
• CDK/Material: 16.2.9
• Browser(s): Firefox
• Operating System (e.g. Windows, macOS, Ubuntu): Windows 11