I didn't even notice he was colorblind (or maybe I forgot)

WHAT

Same n i’m a little confused.. it’s that he can’t see green right

I'm not sure but I think he sees red as green, this is why he got scolded for not being more careful with traffic lights

Wtf how did I miss this

Ikr, I looked into it apparently in the 1st chapter, the lady from the coffee shop tells him to make sure to check the traffic lights

Yes he messed up crossing traffic signal twice earlier at the time of searching jin and when he was carrying jin to hospital in rain. This also means he cannot see blood when jin was heavily wounded.