At this point in time, the staff are split in their opinion on that matter,
@Aeleth
Some believe the colourer should obtain permission first, while others believe that this is essentially policing scans, and that's a can of worms we shouldn't be opening.
If we did start policing scans, where will it end? It's a slippery slope that is not going to end well - there are a lot of scans that people would want banning, stuff like sniping, bad translations, etc.
Hopefully, having the coloured manga on a separate ID will reveal the actual level of interest in it. If no one's interested in it, no one is going to bother with the colouring.