css-color-adjust-1 "forced colours mode" re-introduces a privacy concern

[mallory]

I reviewed [css-color-4] and found that the deprecated systemcolors are necessarily back because of the use of forced colors mode. Even as per the current privacy and security considerations section of [css-color-adjust-1]:

{{
Applying user color preferences via color schemes or forced colors mode expose the user’s color preferences to the page, which can increase fingerprinting surface.
}}

It would be better if these were only available to the user-agent in order to do the color mapping.

[css-color-4] https://drafts.csswg.org/css-color-4/#deprecated-system-colors
[css-color-adjust-1] https://drafts.csswg.org/css-color-adjust-1/#privsec

[fantasai]

@mallory We've made some technical changes that make this more possible in #4915, however see #5710 for current discussion on this particular question.

[fantasai]

Closing as duplicate of #5710 (since the discussion is there).