set_color_blender - Man Page

#include <allegro.h>

void set_color_blender(int r, int g, int b, int a);

Enables a color blender mode for combining translucent or lit truecolor  pixels. Applies only the hue and saturation of the source image to the  destination image. The luminance of the destination image is not affected.

set_trans_blender(3), drawing_mode(3)

set_trans_blender(3).