Please see the picture before you read.
Why do some of the circles appear bright and some dark?
Before banning phase began only me and Janna were bright, then when it was Jungles turn to ban, his lit up.
Anyone know what this signifies/means?
The bright circle indicated that the player is going to feed. http://www.auplod.com/u/udpoal6c174.png
Bright= they already locked in that champ and is going to play that champ that game
Dimmed= they are telling you they want to play that champ (so you don't ban it), but haven't locked in yet (haven't had a turn to choose the champ they are playing)
Hope this helped! ^-^
