I use black International Interspeed Ultra on the hull and white Trilux on the outdrive, trim tabs and waterline.
My reasoning for the black is that, all growth needs sunlight so the less light reflected about under the boat the less growth, well that's my theory.
launched June 2005 took it out Sept 2008, over 3 years afloat and only a thin brown slime to pressure wash off, but then I'm moored at Wareham in fresh water.