This thread shows a 4 point curve to interpolate the RBG numbers:
http://www.blitzbasic.com/Community/posts.php?topic=76794
Maybe this would help? (Sorry that link is for a 4 point curve)
http://efg2.com/Lab/Graphics/Jean-YvesQueinecBezierCurves.htm
http://www.blitzbasic.com/Community/posts.php?topic=76794
Maybe this would help? (Sorry that link is for a 4 point curve)
http://efg2.com/Lab/Graphics/Jean-YvesQueinecBezierCurves.htm