How Michael Keaton knew it was time to get out of the Batman moviesS

Michael Keaton tells the L.A. Times that he wasn't as happy with Batman Returns as with his first Batman movie. And then he had second thoughts about doing a third movie. Here's why:

"I knew we were in trouble in talks for the third one when certain people started the conversation with ‘Why does it have to be so dark?' ‘Why does he have to be so depressed?' ‘Shouldn't there be more color in this thing?' I knew I was headed for trouble and that it wasn't a road I was going to go down."