colourless
adj. 无色的；不生动的；颜色黯淡的
例句
Pure air is colourless and odourless.
纯空气是无色无臭的。
《新英汉大辞典》
Her face was colourless, and she was shaking.
她脸色苍白，全身发抖。
《柯林斯英汉双解大词典》
SO2 is a colourless gas with a sharp odour.
二氧化硫是一种无色气体，带有刺鼻的气味。
