Equation for determining color "closeness"

On page 93 in Chapter 4 (Creating Accessible Content) of "Constructing 
Accessible Web Sites" [1], Jim Thatcher writes, "It is clear that good 
contrast occurs when two colors are close to complementary. 'Closeness' can 
be calculated as if the R G B colors are points in the three-dimensional space:
Distance = ( (R1-R2) ^2 + (G1-G2) ^2 + (B1-B2) ^2) ^1/2

[1] http://www.jimthatcher.com/book.htm

wendy a chisholm
world wide web consortium
web accessibility initiative

Received on Friday, 29 August 2003 18:38:20 UTC