adj : having or appearing to have only one color
If everything in your room is brown, your room is monochromatic — all of one color.
In physics, monochromatic describes light that has the same wavelength so it is one color. Broken into Greek roots, the word shows its meaning: monos means one, and khroma means color. Things that are truly monochromatic are rare — examine the green leaves of trees and you’ll see lots of different shades.
[ source : vocabulary.com ]