GradientColor

function GradientColor(color1, color2: TColor32; frac: single): TColor32;

This function will return the color that's a blend of color1 and color2, where the weight of each color depends on frac.

frac <= 0 Result = color1

frac >= 1 Result = color2

else Result = color2 *frac + color1 *(1 - frac)

frac <= 0	Result = color1
frac >= 1	Result = color2
else	Result = color2 frac + color1 (1 - frac)