I think it is just edits. Almost all companies used enhanced images to make a listing look more appealing. Often where most customers feel they've been mis sold
Quite possibly but to me that looks like a photoshop job.Is someone maybe unfamiliar with reflective surfaces?
I don't think they use renders, I remember reading this years ago though; http://www.theverge.com/2013/5/8/4311868/the-illusion-of-simplicity-photographer-peter-belanger-on-shootingGo look at the 360 views and animations on the website or in the app, It just reflects in an "unexpected" way. I'm also pretty sure Apple has been using renders for most product shots for years now.
As for the colours, there are threads where people show of their watches so you should be able to get a feel of the different bands under different lighting conditions...
They're real photos that are eventually converted into renders for consistency.I don't think they use renders, I remember reading this years ago though; http://www.theverge.com/2013/5/8/4311868/the-illusion-of-simplicity-photographer-peter-belanger-on-shooting