At the moment safecoin is a SD type known to vaults (they generally dont care SD type and treat all the same). So the vault network can confirm safecoin creation through it’s steps (created at a PmidManager group → NaeManage → close to farm attempt → NaeManagers (close to safecoin address) → back to Original group) this gives a load of security and makes it very hard to game.
Due to this then coloured coins may not have the same security (but so we need it, we are being ultra cautious here).
So I would say at the moment coloured coins are not able to be secured as effectively as safecoins. This does not mean the cannot, but we do need to look deeper there, of course after we get everything else running 