I have found that color is not generally indicative of quality. With certain varietals, like Pinot, oftentimes there is a direct correlation between color and tannin levels. But that said, I think color is 'used' by tasters to develop pre-conceived notions of a wine prior to tasting it . . .
One last point - color certainly is important to note as you track the aging of a wine . . . oxidation will lead to a premature changing of a red wine to more of a brick color, and a white wine will really become quite amber with oxygen. This therefore can be a clue to the taster . . .