"mostly white" is always the advice given... Technically it depends on the company. Personally I have not heard of cadre taking plebes shoes from them... that being said, I wouldnt wear neon green shoes. Stick to "mostly white" and you'll be fine
When I did detail, shoes was really the last thing on our minds. We really just wanted to see the plebe go out there and give 100%. We also recognize that some people need different running shoes due to their running style and so they won't hurt themselves.
But like its said above, I wouldn't specifically buy the hot pink or neon green shoes unless I can back myself up by running pretty darn fast.