Palm Centro 690 (CDMA)

Ok, just upgraded my plan and got the Centro a few days ago. So far so good. The keyboard will take some getting used to but love the touch screen. My biggest problem and question is....is there a BACK button on this phone? Before this I had a Blackberry Curve and I loved it. The only thing the Centro has over it is the touchscreen. There was also a huge "back" button on the curve and most other phones that I can't seem to locate on the Centro. I hate navigating around, as I'm trying to get used to where everything is and I can't go back to the previous screen without hitting one of the direct link buttons. I've looked in the manual and can't find anything. HELP??? Also, I have a red one and it looks a bit "pre-pay-ish". I was thinking about exchanging it for black....suggestions? Oh, I'm a recent college grad, no tech geek or anything...feature wise, this phone is perfect for what I need it for.