Can you only use white and black wires on a 2 pole breaker?

Typically the black wire is "hot", and the white wire is neutral. A 2 pole breaker is most commonly used for 240 V, and as such, you would typically use a 3 conductor wire, with black, red and white (+ ground). In a typical application, the black and red are used in the 2 pole breaker, and neutral is connected to the neutral bar in the breaker panel.