al_color_rgb_to_hsv
void al_color_rgb_to_hsv(float red, float green, float blue,
float *hue, float *saturation, float *value)
Given an RGB triplet with components in the range 0..1, return the hue in degrees from 0..360 and saturation and value in the range 0..1.
See also: al_color_hsv_to_rgb, al_color_hsv
Examples: ex_color