procedure RGBtoHSL(RGB: TColor32; var H, S, L : Single); overload;
procedure RGBtoHSL(RGB: TColor32; var H, S, L : Byte); overload;
Conversion from RGB to HSL color space. The H, S and L components are returned in corresponding var parameters ranging from 0 to 1 for the float version and 0 to 255 for the byte version.