Attached Link: http://www.easyrgb.com/math.php?MATH=M18

Dunno if this'll help or not, but I googled it: (BTW - "to google" is now an officially recognised word:-]). Got this from the attached link..- I leave it to you wizards to work out the nodes required:-).... RGB to HLS: var_R = ( R / 255 ) //RGB values = From 0 to 255 var_G = ( G / 255 ) var_B = ( B / 255 ) var_Min = min( var_R, var_G, var_B ) //Min. value of RGB var_Max = max( var_R, var_G, var_B ) //Max. value of RGB del_Max = var_Max - var_Min //Delta RGB value L = ( var_Max + var_Min ) / 2 if ( del_Max == 0 ) //This is a gray, no chroma... { H = 0 //HSL results = From 0 to 1 S = 0 } else //Chromatic data... { if ( L < 0.5 ) S = del_Max / ( var_Max + var_Min ) else S = del_Max / ( 2 - var_Max - var_Min ) del_R = ( ( ( var_Max - var_R ) / 6 ) + ( del_Max / 2 ) ) / del_Max del_G = ( ( ( var_Max - var_G ) / 6 ) + ( del_Max / 2 ) ) / del_Max del_B = ( ( ( var_Max - var_B ) / 6 ) + ( del_Max / 2 ) ) / del_Max if ( var_R == var_Max ) H = del_B - del_G else if ( var_G == var_Max ) H = ( 1 / 3 ) + del_R - del_B else if ( var_B == var_Max ) H = ( 2 / 3 ) + del_G - del_R if ( H < 0 ) ; H += 1 if ( H > 1 ) ; H -= 1 } Cheers, Diolma