can you make the glasses and magic crayons so it is every new crayon need to be linked to the glasses to if there asre people that cant get access to that room cant walk in to it.

if you got the crayon linked to your glasses you can link more ids to your glasses so when your crayon is empty you can link te new one

You can't make non-reproducible colors. But you can mix crayons (by placing more than one in crafting grid). That way you can create hard to guess colors (with all 9 fields there are about 300 000 combinations possible). And then process can be repeated.

This solution is little bit harder, but I think it's much more interesting.