I once made a light source with 12 18" flourescent tubes. I rapped alternating tubes with green and blue roscoe filters, and I could control each colored bank independently. I used high quality electronic ballasts. If you use the high CRI bulbs, you get about 1 stop faster printing with the blue (high contrast) bulbs.
There are some issues. The bulbs are brightest in the middle, and so this need to be evened out. Second, light output varies with temperature. So as they heat up, they get brighter, at least until they are about 110F. Higher temps lead to reduced output. So, either you need some type of light measuring timer, ala Metrolux, RH Designs, Zone VI..., or you should leave the light on all the time to stabalize temp, and use a shutter to control exposure.
After futzing with my DIY head for a while, I eventually bought a different 8x10 enlarger. It came with a standard color head, which I prefer. Given the cost of 8x10 enlarging equipment, I'd look for a cheap dichroic color head, unless you simply want to monkey around.
