I was up there as well, I used instagram on my old iPhone 3G (as well as rocking a DSLR) and had barely any problems at all. In fact I found the whole experience of the app very liberating, literally taking shots on the phone, styling them, uploading them and having people commenting, liking and following me within in minutes of them going up. I can't say I've tried Color, but I see it struggling to beat the penetration that instagram has achieved.