Green key? I think its the immobiliser... after a few kicks, it disengages and allows the car to start. Nothing uncommon. happens in most WRXs but they ahve a crunching sort of sound when you turn the key.

Only probs i had when i turn and stop just before its about to fire... then it takes sometime for it to start after that. Probably waits for the gases to clear before trying to ignite again.

My 2 cents