朱に交われば赤くなる (しゅにまじわればあかくなる): people will take on the characteristics of those who surround them; when mixing with vermillion, one becomes red

people will take on the characteristics of those who surround them; when mixing with vermillion, one becomes red

Mix with vermilion and you turn red. Most often said about the company a young person keeps, and it cuts both ways: good company colours you too.

A Japanese proverb (ことわざ)