I've seen the Color Pallets used for uplighting and it will work, but they're kind of "old technology". The newer uplights use 10mm or 1watt LED's (the pallets are 5mm I think). If you're going to buy anything now, I'd suggest paying attention to the LED size.
I've been using the Chauvet Slimpar64's and I'm pretty happy with them. You can get almost any color, but still it has its limitations. If you're really concerned with genuine color mixing, then you have to look at RGBA or RGBW or something that has white/amber LED's. The slimpar64 and color pallets are all RGB.