AOk. So I want to make some character figures for a birthday cake. I might have a little practice first. I'm gonna use sugarpaste and cmc powder as it's cheaper. What I was wondering. Would it be easier to use coloured icing. Or use white icing and paint it??

AI wouldn't paint if you've never tried it. I actually wouldn't do any of that without practicing first. Aren't you curious about the process and would want to know how much time to estimate for future projects? I would want to know that I was on the right track in case something happened that I'd need help with.

Color the sugarpaste first.   There are many tutorials on the subject and I would recommend your watching them first to get an idea on how it's done.