All the cold pressed virgin sunflower oil in shop is in transparent bottles. Does it mean it is already rancid?
I'm fairly sure the manufacturers and supermarkets are not in the business of exclusively selling rancid oil.

Sunflower oil has a shelf life of around two years. The turnaround time for oil is fairly high, so the bottles probably haven't been out on a relatively bright shelf for all that long. Check the use by date and as long as you have, say, a year to use the oil, it will almost certainly be fine.