I have always done them the same as any other legs. Lots of work at home to get the hair. Then get all the hair up using an EZ Comb adhesive. Once all the hair is going the right direction set it good using a leg and tail adhesive, then give it a few good coats of a white touch up paint.
Just like you do on a solid black one. I use tail adhesive, but that's just personal preference. Be patient and take your time and don't get too carried away and you won't have to paint.
baby powder works, but I just find the touch up easier, I agree with white legs and taking your time you shouldnt need the paint to cover it, but I use it anyway cause it adds a little mass
Use a piece of cardboard or paper to cover the white areas when you paint the black areas and vice versa. This takes some practice to get that natural look, but it's the best way to paint one with colored up legs.