Yeah he was. Luigi had a green cap and shirt, and blue overalls.
And by the way, the Master at gaming, in SMB2 Mario wasn't faster per se, he just didn't slow down as much when he was carrying something. When unburdened, I believe they run at the same speed. And yes, Mario could be said to be stronger than Luigi in SMB2 cause he lifts stuff off the ground 2 times at fast as Luigi.