Color Contrast Checker
By Pete Freitag
I just found this Color Contrast Checker web site on del.ic.ious. You just give it your foreground (text) color and background color, and it will tell you if there is enough color contrast "when viewed by someone having color deficits or when viewed on a black and white screen" (as defined by the W3C).
The tool will indicate that the colors pass the test if both the color difference and the brightness difference exceed their threshold. It will indicate that it sort of passes if only one of the two values exceed their threshold. And finally, it'll fail to pass if neither value exceeds its threshold.
I have seen enough hard to read web pages (even by very skilled programmers) that I thought it would be worth while to post this.
Color Contrast Checker was first published on January 13, 2005.