It has been outside but under a good quality, lined bike cover. I don't put the cover on when the bike is wet, but wait for it to dry. I don't think that it was wet for an 'extended time'.
This is the original paint, definitely not a repaint. There is no white primer showing, just the black and the thin clear coat. When moisture gets between the layers it looks grey. It's difficult to get a really good photo, so it may look like white – it is in fact the 'lifted' aeas of the clear coat.