Humans are not meant to photosynthesise for a reason. Imagine the product of fake tans coming from that hypothesis; instead of orange, some girls would probably aspire to be lime green or something, amirite?

I always wanted a lime green partner. It would compliment my dining room motif.

If we used photosynthesis though, then we'd all have to spend more time outside and all the tans would be real. Fake tans wouldn't exist in that reality most likely.