We have always wanted the Concorde, but it never fit in with tight enclosed regions. You couldn’t really enjoy it at full speed and altitude until Global Flight is ready. That said, it is confirmed at least that sooner or later it will be added, but the model will need to be worked out. I’d expect this not to be something that will be ready at the same time as Global, but it will be coming.
Also colors are often skewed a bit by the time of day lighting or angle. But it’s fairly minor and low priority all things considered. If anything can be corrected, it will be eventually. :)