An acrylic paint will serve you best with a compatible clear coat over the top. You only want to lay the paint & clear on very thin or it will crack when the rod flexes. Your best bet is to use acrylic spray cans designed for automotive use. You should be able to get them at any good auto parts retailer or better still from a spray paint supplier shop. A can of colour & a can of clear will cost you less than $40. If you have a compressor & an air brush you can do it that way. 100ml pots from a spray paint supplier should only cost $10-$15.

Be sure to remove all traces of the old coating or the paint will not stick. That means removing guides & the foregrip, sanding the blank back with 800 then 1200 then 2500 grit sandpaper, then wiping the whole thing down with methylated spirits to remove any oils & residue. When sanding be very carefull to only remove the coating without taking anything off the blank material. If you gouge the blank or take too much material out of one section you will compromise it's strength & action.

I have used the plastsizer paints used for the plastic chairs they come in a variety of colors and you can spray it on the most flexable blank and it will not crack or split under load

Thanks guys I'll be giving the shops a visit soon