I'm re doing my whole room

My wall is dark purple and my bed sheets are gray.

Black would be a neutral, if you want bright try a safety color or fluorescent color. If you want something different you can try and wood grain with purple and gray to blend in,,or black with glows in the dark splatter.

My niece is always changing her room colors, currently she has lime green walls on 2 sides, safety yellow/green on the other 2, black ceiling with glow splatter and hand painted planets, at night with the black light they glow bright and are quite striking.

She uses grays, blacks and earth tones that blend quite well with everything, she wants to paint the floor but her mom says no and she will have to settle for custom inlay carpet tiles she will place herself.

Hope this helps

make it like a shiny dark brown

if you really want it to pop go with yellow if you want contrast then charcoal for suttle use black

I'm re doing my whole room

My wall is dark purple and my bed sheets are gray.