Seth,
I use the Testor's brand model enamels. Both spray and in the small bottles. I use the spray to do the cap dips (one coat flat white, two coats color) and the other to do the cresting. I have never had any trouble getting it to stick to the carbon shafts. I always wipe the bare shafts down with acetone before painting.
Here are a few pictures of some arrows I have done. These are a few years old.
Here are some wood shafts I made-up.
These are wood shafts footed with sections of alum. arrow (increases FOC and can use screw-in points)
All of these were done with the Testor's paints. The paints are very durable (I don't use any clear coat and have arrows I have used for 4 or 5 years) and It's reasonably priced.
OkKeith