Please help me find? Green/Brown Haired FWB

So I read a manhwa probably in the last year or 2. I have no idea what the actual plot is. I feel like it might be a work place one. I don’t remember anything about the MC or ML.

What is sticking out is the MC’s friend who was initially his FWB. The FWB had like brownish hair that looked green. I remember the comments kept calling him green-haired. The FWB never wanted to settle down & slept around a lot. And, once the MC stopped sleeping with him because he liked the ML the friend confessed his feelings way too late.

I’m not sure if the friend even played a big part in the actual story. I can’t remember if I even liked this one, but it pops into my head sometimes, and I just need to know what it is.

Thank you!!