avoid "color contrast"

Dear WCAG WG,

Please avoid the phrase "color contrast".

Some places we've found it:
* http://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-contrast.html
* http://www.w3.org/TR/2008/WD-UNDERSTANDING-WCAG20-20080430/visual-audio-contrast-contrast.html

Additionally, several pages include "color contrast" in the Resources listings. We wonder if it would be worthwhile to add a note there, e.g., something along the lines of what we have at <http://www.w3.org/WAI/eval/preliminary#contrast>: This accessibility requirement is sometimes called sufficient "color contrast"; however, that is incorrect — technically it's "luminance contrast"...

Thanks,
Shawn for EOWG