Hi gastyli,
your A580 is perfectly fine, no need to return it to the shop.
The AF area should light up in red for focus confirmation when using the OVF. When using the LCD, they light up in green. Unfortunately the manual is not at all clear about this, but you find a hint about the red light in the OVF on page 48 of the English manual. Guess the manual could do with some revision...
I have the previous model, A550, and it is exactly the same.
Cheers
Jules