Hey so in the hardware store I went just before I reached Diamond City and I took the yellow paint, obviously I wasn't aware of an up and coming quest to use that paint, is there another place I can acquire Yellow paint? I'm a Xbox player FYI.

Not a sure way place I can think of, but its not some quest related item, so you can find it in old ruined hardware stores, in the utility parts of larger buildings, sold by traders, etc.

Hardware stores, primarily. I've come across it in several places.

u can actually finish the quest by just giving the guy the blue paint and then that'll be the new color xD, i dont think it really changes anything if you do that, you'll just get a blue wall xD

Yes but I've gotta do all the optional, just got to! Lol I hear Bunker Hill and Cambridge, where are these located please?

Lol... Shop sells it!

or any paint, and Abbott and the city will be mad at you bc it's supposed to be green

There's a paint mixer there I was able to click on and it put green paint in my inventory.