No. As long as you can keep out uncontrolled sources of unsafe light they can be any color. To be able to see clearly with a safelight, having light colored walls and ceiling is a good idea.
My Father used the bathroom for his darkroom (much to our dismay) but he did keep all light out by sealing cracks in the windows and doors while he was in there and he shot black and white so he was able to use a safelight.
Have you considered the cost of Hazardous Disposal? You are going to have Hazardous Waste.
Why not use the Green Darkroom (it's called a computer)?
the ones i have been in dont have black walls, if theres no light then it wont reflect off white silver or black or purple............hence a "darkroom" - so any colour will do you only see it if the lights are on......