Anyway... with all due respect to ROL's comments in post 13 above, I'll just restate a basic point: in b&w, many tones can be transformed into another simply by adding or subtracting light on the subject. In colour, that's not true at all; if you add light to blue you just get (lighter) blue etc.... you just get the different shades and tones and not a different hue like red or green or whatever. So the relationships between the hues are very different from the relationship between (b&w) tones. It takes more than added or subtracted white light to relate them.
On the subject of how to "see" a colour composition, let me suggest looking for compelling combinations of shapes and tones, just as you would with b&w.
To help with that, here's a compositional exercise that may prove useful or at least amusing. Find a compelling subject and defocus so that you don't see sharp boundaries but rather see blurred images through the lens. This may help you to see how the colours interact rather than all the minor complexities.
This little exercise works with b&w too, of course.