My point was actually to make the color change very graduate, so the "index" solution is probably what I'm looking for.
Since the colors are described by RGB, I'm guessing it's not easy to play with those indexes in order to pass gradually from a color to the other. Each of the indexes describe an amount ranging from 0 to 255 right? (by the way, in opposition to what you said, white would be [0,0,0] and black [255,255,255] wouldn't it?). Since each intermediate color has its own ratio of red green and blue it's surely going to take some effort to find my way through this.
Has any scripts been already written that uses this in a way or another so I could get some inspiration?
Dan I just saw your post while writing this one, regarding what you wrote, is there any way to describre colors in rubby other that the RGB way? Like you say, a linear "strip like" color space would be perfect (and I believe doesn't exist)