colouring
noun UK (US coloring) uk/ˈkʌl.ər.ɪŋ/ us/ˈkʌl.ɚ.ɪŋ/
(APPEARANCE)
[ S ]（人的头发、皮肤和眼睛的）总体颜色
the combined effect of a person's hair, skin, and eye colour
Their colouring is so totally different that you would never think they were sisters. 她们的头发皮肤颜色大不相同，你绝对不会想到她们是姐妹。
(SUBSTANCE)
[ C or U ]（食用）色素
a substance that is added to food or drink to change its colour artificially
It says on the label that no preservatives or artificial colourings have been added. 标签上说没有添加任何防腐剂和人工色素。