bestfit_color - Man Page

#include <allegro.h>

int bestfit_color(const PALETTE pal, int r, int g, int b);

Searches the specified palette for the closest match to the requested  color, which are specified in the VGA hardware 0-63 format. Normally you  should call makecol8() instead, but this lower level function may be  useful if you need to use a palette other than the currently selected  one, or specifically don't want to use the rgb_map lookup table.

Returns the index of the palette for the closest match to the requested color.

makecol8(3)

makecol8(3).