If you don't know, I recommend brown. They are tactile, so you can feel when you actuate the key and they are not as obnoxious as blues.
Do you never use the num-pad or almost never? Because if you use it once or twice a month you might want to consider the quickfire TK:
If is only one row wider than a normal tenkeyless, but it has the numpad an arrow keys, delete, etc all merged into a numberpad. I have it and after a few days, switching between the two modes becomes second nature.