You're Blue!

It is an inside joke me and my friends made when we played Roblox back in our school days. Whenever one guy said that we are allowed to join the game he is in but that friend's status is still blue (meaning online but not in a game), that phrase is what we used to rant on the one who hosted.

bro1: Yo bros! I got found a good game to play! Join me now!
bro2: YOU'RE BLUE! Stop cappin!