Saw this on twitter:
A: マオにゃん、シドギャの彼女が出来ない僕に一言くれたら幸いです ...
What is 染めちゃえ here?
Just an idea: Maybe it means that someone has been in contact with X for so long that they have been influenced?
Like a white shirt would get a bit blue if you wash it together with blue clothes. A metaphor that can be found in French with "déteindre".