Here is a video I made of the three main Jedi/Sith colors (blue, green and red).http://www.youtube.com/watch?v=vJb4IW_APz4
They are all being driven by the V2 driver board, so it's a fair comparison other than the fact that the green and blue are using the light-dueling blade core and the red is the heavy dueling blade. Not sure if that makes a difference for brightness. In person, they all look amazing to me.
My friend saw this and said it looked like 'saber porn.' :o
I'm afraid I have to agree, lol.