/* utility routine for HLStoRGB */
WORD HueToRGB(WORD n1,WORD n2,WORD hue)
{
    /* range check: note values passed add/subtract thirds of range */
   if (hue < 0)
      hue += HLSMAX;

   if (hue > HLSMAX)
      hue -= HLSMAX;

   /* return r,g, or b value from this tridrant */
   if (hue < (HLSMAX/6))
      return ( n1 + (((n2-n1)*hue+(HLSMAX/12))/(HLSMAX/6)) );
   if (hue < (HLSMAX/2))
      return ( n2 );
   if (hue < ((HLSMAX*2)/3))
      return ( n1 + (((n2-n1)*(((HLSMAX*2)/3)-hue)+(HLSMAX/12))/(HLSMAX/6)));
   else
      return ( n1 );
}

DWORD HLStoRGB(WORD hue,WORD lum,WORD sat)
{
   WORD R,G,B;		      /* RGB component values */
   WORD  Magic1,Magic2;       /* calculated magic numbers (really!) */

   if (sat == 0) {	      /* achromatic case */
      R=G=B=(lum*RGBMAX)/HLSMAX;
      if (hue != UNDEFINED) {
	 /* ERROR */
      }
   }
   else  {		      /* chromatic case */
      /* set up magic numbers */
      if (lum <= (HLSMAX/2))
	 Magic2 = (lum*(HLSMAX + sat) + (HLSMAX/2))/HLSMAX;
      else
	 Magic2 = lum + sat - ((lum*sat) + (HLSMAX/2))/HLSMAX;
      Magic1 = 2*lum-Magic2;

      /* get RGB, change units from HLSMAX to RGBMAX */
      R = (HueToRGB(Magic1,Magic2,hue+(HLSMAX/3))*RGBMAX + (HLSMAX/2))/HLSMAX;
      G = (HueToRGB(Magic1,Magic2,hue)*RGBMAX + (HLSMAX/2)) / HLSMAX;
      B = (HueToRGB(Magic1,Magic2,hue-(HLSMAX/3))*RGBMAX + (HLSMAX/2))/HLSMAX;
   }
   return(RGB(R,G,B));
}
// end sample
Написал Вася Пупкин.