Blue Leader

is a Gradient Skin added in the v0.7.0 "" update on January 31, 2018. It is similar to the Red Leader, and a random player is picked from the Blue team early in the game to be the leader, granting them this and several other perks. The Blue Leader is colored blue and appears bigger in size than normal players, but the code says that doesn't have to due with the skin meaning that it from the Team Leader Perk.