The window and door frames are pre-painted before installation to prevent color mismatch later.

pre-painted 是由前缀 pre-（表示“预先”）和动词 paint（喷漆、涂漆）的过去分词 painted 组合而成，字面意思是“预先喷漆的”。这里指门窗框架在安装前就已经完成喷漆工序。