sneaklyfox
Legend
The wavelengths of yellow and green are towards the center of the visible light spectrum (ROYGBIV). They are factually easiest for the human eye to detect. This is why road-workers wear green/yellow uniforms with white reflective strips.
Red and purple are slightly more difficult to identify, especially in low light situations.
The effect on cubing would be minimal presumably, but still potentially existent.
Actually I see a lot of orange uniforms with yellow or white strips. I figure whatever stands out in the road is best. Pylons are usually orange. I've never seen green uniforms. And I find yellow/white most difficult to discern in low light situations while red/orange is easiest because their shades contrast more.