expression, godan verb (-ru)
people are shaped by their environment; walk with the wise and become wise
Proverb meaning that one's character is influenced by the company one keeps, just as something dyed in ink becomes black. The literal image is 'if dyed in ink, it becomes black.'
墨に染まれば黒くなるというから、友達はよく選んだほうがいい。
They say 'if dyed in ink, it becomes black,' so you should choose your friends carefully.
彼は悪い仲間とつきあううちに、墨に染まれば黒くなるで、すっかり人が変わってしまった。
As he hung out with bad company, true to the saying 'walk with the wise and become wise,' he completely changed.