I'm loathed to criticise, especially given TNG S1 on Blu ray was pretty phenomenal, but I don't remember this topic cropping up in any of the documentaries. Perhaps it's mentioned in a commentary I've maybe skimmed over or is yet to come.
Then again if it only boiled down to what colour a producer thought looked good on Patrick Stewart... not the most interesting story ever! Not compared to how they decided on whether he needed a hairpiece or not.
There's something like a decade spent at the movies, where department colours didn't play such a large part in Star Trek at all. Just a collar here or strip of cloth or bit of braid there.