T-Energy imbues all creatures that are infected/affected by it with a blue light. The T-energy pumps can be seen all over Ancaria as they make their way to the Great Machine. This Easter Egg references Sylvester Stalone from the Rambo series against one of the books that can be found in the game that explains some of the fundamentals of T-Energy:
Book 5 - T-Energy
"What is it?"
"What does it do?"
"It glows blue."
The following video/scene is taken from the last movie in the series as he explains to a curious onlooker what the "blue light" in his equipment is for: