Please Check Colors for Your Design.

for your infomations

Color Brightness

The range for Color Brightness is 125.

((Red * 299)+(Green * 587)+(Blue * 114)) / 1000

Color Difference

The range for Color Difference is 500.

abs(R1-R2) + abs(G1-G2) + abs(B1-B2)

abs means absolute of value.

from W3C Working Draft