colour in
phrasal verbcolour something in
- to put colour inside a particular area, shape, etc. using coloured pencils, crayons, etc.
（用彩色笔、蜡笔等）给…涂色，给…着色 - I'll draw a tree and you can colour it in.
我来画一棵树，你给它涂上颜色。
- I'll draw a tree and you can colour it in.