The painter uses dark colors to express melancholy.
Tips
usage
暗色 is the opposite of 亮色 (bright color). For UI/dark mode you'll see 暗色模式 on Chinese apps. Note 暗 (dark) versus 深 (deep) - 深色 (deep color) is more common for things like navy or burgundy; 暗色 leans toward dim or shadowy.