al_is_color_valid - Allegro 5 API

       Checks  if  all components of the color are between 0 and 1.  Some of the color conversions in this addon
       support color spaces with more colors than can be represented in sRGB and  when  converted  to  RGB  will
       result in invalid color components outside the 0..1 range.

       al_is_color_valid - Allegro 5 API

       5.2.3

Allegro reference manual                                                              al_is_color_valid(3alleg5)

              #include <allegro5/allegro_color.h>