What is this?
We check your foreground colors, to see if they fulfill the W3C Color Guidelines.
This test has two parts:
Brightness fails if the contrast between your foreground and background color is too low. Try chosing a darker/brighter tone.
Difference tests if the hues of your foreground colors are too similar to the background. This can be an issue for color blind people, for example. Try changing your color to a different hue.
Please consider this a recommendation, not a rule. The Guidelines are very strict and many great color schemes fail in this test.
