If a site use css gradients with carefully tuned values -say, for glass buttons- they will easily "use" 5-10 colors for each gradient. It would still look like

If a site use css gradients with carefully tuned values -say, for glass buttons- they will easily "use" 5-10 colors for each gradient. It would still look like a solid color + gloss, caustics and shadow, so from a design point of view it might be fair to treat each gradient as one "color".