if someone or something blends in, they are similar to the other people, objects, buildings etc around them, and so they seem appropriate or you do not notice them (与周围事物)十分协调,融为一体
blend in with:
The new library blends in perfectly with the surrounding buildings. 新图书馆与周围的建筑十分协调。
Security men were trying to blend in with the crowd. 保安人员试图混入人群中。