Which would you choose to keep rods or cones? And why?

Rods are responsible for vision at low light levels (scotopic vision). They do not mediate color vision, and have a low spatial acuity. Cones are active at higher light levels (photopic vision), are capable of color vision and are responsible for high spatial acuity. The central fovea is populated exclusively by cones.

Rods, if I have to see in black and white might as well see in the dark