[whatwg] CSS2 system colors in legacy color values

Simon Pieters simonp at opera.com
Sun May 23 14:49:27 PDT 2010

On Sat, 22 May 2010 21:06:53 +0200, L. David Baron <dbaron at dbaron.org>  

> The "rules for parsing a legacy color value" in
> http://www.whatwg.org/specs/web-apps/current-work/complete/common-microsyntaxes.html#rules-for-parsing-a-legacy-color-value
> specify that CSS2 system colors should be accepted, and that they
> should be converted to a simple color.
> It seems like a substantial amount of work to get dynamic change
> handling correct for this case, since system colors can change
> dynamically when the user changes system appearance.  I'd really
> like to avoid having to add dynamic change handling for this, and
> I'd also like to avoid having to make system colors dynamic in CSS
> but static in HTML.
> What was the motivation for adding support for CSS2 system colors

IE compat.

> (which I would note are deprecated in css3-color) to legacy HTML
> color values?  What implementations support them,

I think WebKit and IE.

> and do they
> respond to dynamic changes properly?

I don't know.

It appears that Opera and Gecko don't support system colors. I wouldn't  
mind not supporting them, but it could be interesting to research how many  
pages it affects.

Simon Pieters
Opera Software

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