Like the matte black head idea. I think you should stick to one "bright" color on the sole. If you had red, and blue, and green, I think it looks silly. Most of the sharpest driver heads are fairly "stealth" colored with one nice bright accent color. Seems to be the modern industry trend too - Cortex is red, Epic green, Rogue blue, TS2/3 white, F7 and F8s similar.
TM is different doing the BMW red/blue/white, I guess, but I've never heard anyone gush about how nice those heads look.
I think the stealth + 1 color is a modern, sleek look that would be appreciated by today's buyer. Like a black Camaro with gray rims, red brake calipers, and a stripe. Blue or whatever else would look nice too.