colourless
adjective UK (US colorless) uk/ˈkʌl.ə.ləs/ us/ˈkʌl.ɚ.ləs/
(NO COLOUR)
无色的
having no colour
Water and glass are colourless. 水和玻璃是无色的。
Carbon monoxide is a colourless, odourless, poisonous gas. 一氧化碳是一种无色、无味的有毒气体。
(BORING)
不刺激的;不精彩的;平淡无趣的;乏味的
not exciting or not interesting
It is a rather grey, colourless city, with few interesting sights. 这是一个灰暗、了无生趣的城市，有趣的景点寥寥无几。