About a week before the tracker shows your BW is confirmed, it'll be confirmed at the factory, but only your dealer will know at that point.
I had a first-hand change cock-up with mine and my dad's GTDs. I ordered DBP Manual GTD, my dad ordered a TR DSG GTD about a week later. About a week after my dad placed his order, I had a change of heart about colour and opted to change for TR. Instead of my order changing from DBP to TR, they changed my dad's TR order to DBP. We hadn't realised for a few weeks, then my dad decided he might like DBP for nowt. When they finally changed my order to TR after I said the tracker wasn't reflecting my change, a whole month later and realised their mistake, it was too late to change my dad's back. The car was locked out for changes a week before the tracker showed BW confirmed and built 5 weeks later. His order had leapfrogged mine.