MultiChain solves this in a way which colored coins protocols (on bitcoin) cannot, because every node in a MultiChain network is automatically validating every asset transfer represented by transactions, and this is something which the bitcoin network does not do. In other words, the bitcoin network is blind to the metadata representing non-bitcoin assets, whereas any MultiChain network is not. As a result, the existence of a single transaction in a MultiChain blockchain is enough to prove all of the assets that transaction represents. Of course, you still have to trust the network / validators as a whole.