Visual treatment.
WHAT TO DEFINE
A palette, as named values used throughout.
WHY NAMED VALUES
So a colour can be changed once, and so its purpose is documented.
WHAT CUSTOM PROPERTIES PROVIDE
Values defined once and referenced everywhere, changeable at runtime.
WHAT THAT ENABLES
Theming, including light and dark variants.
WHAT TO CHECK ALWAYS
Contrast between text and its background.
WHY
Insufficient contrast is the commonest accessibility failure, and it is measurable.
WHAT COMMONLY FAILS
Grey text chosen because it looks refined Text over photographs Placeholder and hint text Disabled states
WHAT TO NEVER DO
Convey meaning by colour alone.
WHY
Anyone who cannot distinguish those colours receives no information.
WHAT TO PAIR IT WITH
Text, shape, position or an icon.
WHAT TO RESPECT
The user's stated preference for a colour scheme, where the system provides one.
WHAT TO TEST
The interface in greyscale, which reveals everything depending on hue.
