I'd have to go start mine to confirm but I'm 99% certain the A500 doesn't actually light up the drive light unless it's actively reading/writing.
What you should see is the power light come in dimly as the machine POSTs, and go full bright once the machine has concluded its POST. Once this happens the floppy drive should seek back and forth, then click every few seconds until a disk is inserted. If you have no drive noise then you're in a bad way - electrically it's generally CIAs failing that kills the floppy, the A500 has two of these. Otherwise it could be the drive mechanism itself that's at fault.
Don't worry about the power LED colour, it's irrelevant - they weren't dual colour, but they DID use a variety of colours on the A500 production run. Earlier models tend to have red LEDs, later models have green LEDs. If the machine crashes for some reason the power LED fluctuates brightness rather than colour. You get used to that particular trait... piece of software fails to load, power light flickers, GURU MEDITATION.

But before any of that discussion we need to make sure you can get a picture or all the loading software in the universe is wasted

Just the local Commodore hobo and middle-aged PC hoarder.
eisa on Trademe. A lasting reminder of a Compaq fetish when I was younger.