I love so many colors. It really depends on the exact hue and what it is being used for.
In clothes, I love black and crimson red. I wear a lot green too in different shades.
In sex toys, I am most excited when I see lime green or orange when it comes to plastic and silicone. Still, black or the right shade of red can be pretty damned sexy for a big dildo or restraints. The new Sasha Gray line of glass toys that come in black? HAWT!!!!!!!