Thank you for your reply.
if the colors are FF0000 (Red), 00FF00 (Green), 0000FF (Blue), FF0000 occupy 34% ( from 0 to 34),00FF00 occupy 34%( from 34 to 68) ,0000FF occupy 32 % (from 68 to 100)
the ratio will be "bgRatio='17,34,34' "
17, the 1st starting point of the color Red.
At this point, Red will be PURE Red.
17+34=51, the 2st starting point of the color Green.
At this point, Red will be PURE Green.
17+34+34=85, the 3st starting point of the color Blue.
At this point, Red will be PURE Blue.
What I said is right??
Thank you very much for your reply again.