you definitely do not want anything that light will remotely penetrate. that will kill your roots. White is a very bad idea for pots.
And if you are comparing spending $10 vs. $2 on pots.... the increased yield you see in 1 7gallon pot will more than justify the upfront cost of buying the pots. If you have 7 foot ceilings, get 7 gallon pots.
I ran smart pots last time and honestly didnt see much difference. Harder to flush if anything. Water just runs out of the sides instead of straight down through the roots.
Next run, im going all 7s.
the experimentation never ends