Car stereo just stopped working but red light still glimmers?

Today I drove to the grocery store with the radio working fine, listening to my ipod through the USB connection. I walk into the store, come back out... turn on my car... and the radio does not turn on. The way my radio works is that when it's turned on, everything illuminates blue. When it's turned off the power button illuminates red. Now, the only thing that the radio does, is the power button illuminates red and the clock doesn't even work. Also, what's weird to me, is that even after I turn the car off, the power button is still illuminating red (dimmer than what it would if the car was fully on). So was this after market stereo installed improperly by Best Buy? I had it installed about a month ago. Or is it more like a stereo problem?