I agree with Splais, and add the following from my experience:

My first bipe (I still have it) is a Sig Hog Bipe, done in dark red with white "flashes". I quickly learned how tough it is to see, because of the tight profile, and added big yellow backgrounds behind the "flashes", and made them red, and added yellow on the wings. Visibility is better, but the airplane still is hard to see because of the 42" ws. It is a superb flier, powered with an OS 91FS, which I consider the optimum selection for that airframe. Oh yes, use a 70-oz servo for the ailerons, 'cause you are driving all 4 from 1 servo.

My second bipe (I still have it, too) is a Dave Patrick Ultimate 120, powered with a Saito 150. The Patrick colors and the 60" ws make all the difference in the world in visibility. It is adequately powered with the 150, but not overpowered, and flies better than the Hog, which you would expect due to the greater size.

Happy biping!