At the gallery opening, he made a point to pay the artist a sincere compliment on her innovative use of colour.

pay 在这里是动词，意思是"给予、表达"，常用于表示给予关注、尊重或赞美等抽象事物。 compliment 是名词，意思是"赞美、称赞"，指对某人或某事的正面评价或欣赏。 pay a compliment 是一个固定搭配，意思是"表达赞美"，指特意向某人说出称赞的话语。