How would you see the colour on the lightning transactions?
That's what I'm trying to figure out. It would need to rely on knowing that only certain addresses are on the network.
If the only addresses allowed are A,B,C,D,E,F then you could have A open a channel to B, B to C, etc.
If everyone knows that only those addresses can be used then they could see that no new bitcoins are going to those addresses (thus increasing the satoshis on the network). If someone increases the amount on one of those addresses without conforming to the colored coin, then it would be rejected.
But if A opens a channel to B, then A opens a channel to S (which has a lot of BTC) then A could send a shitload of satoshis to B which represent something else.
I only understand LN at the high level so I'm not sure if this is possible.