Make sure to use correct aesthetics, light blue with white, etc. Some French restaurants choose bold color schemes for their restaurant, like red for example. But you wouldn't put red in let's say a little girl's room, you would most likely choose a nice white and maybe some splashes of pick in some places. Aethetics are a big thing in interior design, and some people might think that you would want to put complementary colors like purple and yellow together, but you wouldn't put bright yellow and purple together in a room, it wouldn't look right, plus it would also strain the eyes. Lavender and white would be a good pair, some bathrooms are painted lavender with white boards.
Street art is often illegal because each building is owned by someone and when someone tags a wall, it's vandalizing that building and that persons property. Hope this helps!
