Plum and eggplant can be cool or warm colors, depending on how it is used and what accent colors are paired with it. Unlike the rest of our home, our bedroom gets very little natural light. We embraced this by going dark with the walls, which really makes the room feel cozy.
Colors used in my room:
Eggplant/plum, grey, and white. I change up my bed linens in order to change my palette. Right now I am using accents of navy blue.
Tips for using color successfully:
A lot of people believe that the less natural light a room receives, the lighter the walls need to be in order for it to appear bigger and to allow for more light. I find the opposite is true; a light color in a naturally dark space feels drab and lifeless, while darker colors are embraced by the space and add depth and warmth.