I use fondant all the time and generally buy the gumpaste flowers from a vendor but a customer requested blk. and red marbled princess roses so I need to make them. which is better fondant or gumpaste, How do I color the gumpaste too?

You color gumpaste the same way you color fondant - put a little shortening on your hands, add color and knead.

I personally would use a 50/50 mix (half fondant, half gumpaste). I made a dozen gorgeous roses last night using 50/50 and they are rock hard this morning. The fondant gives you a little extra work time over straight gumpaste.