BBS wheel model numbers & colour codes?

Oh dear! Looks like Recaro are heading the same way. As you say, getting replacement parts might become tricky unless they are snapped up by another company.

https://www.autoexpress.co.uk/news/363925/recaro-folds-and-wheels-come-bbs-financial-trouble-strikes#:~:text=As%20for%20BBS%2C%20the%20wheel,its%20270%20employees%20in%20Germany.