added threejs format

hello! 

i've added threejs format.
it's a number format (compared to string), with rgb and no alpha
http://mrdoob.github.com/three.js/docs/56/#Reference/Math/Color

so when i get a number in onecolor() i assume it's a threejs format, this assumption may be wrong, there are other formats with alpha also using numbers...
and the output function is threejs()