You should contribute your idea to the Colored Coin project.
https://groups.google.com/forum/#!forum/bitcoinx
I believe what you have contributed and what they are doing go hand in hand. I believe they need help with the client. Which basically is your idea but extendable to any object (I maybe wrong)
I started development on Rarebit before the colored coin group really formed for real and got things going. In my spec, I acknowledge Meni Rosenfeld's paper, which I read when I started my development.
Yes, Rarebit can be thought of as a specialized colored coin protocol (as can mastercoin), and it might be possible to make Rarebit interoperable with colored coin.
The colored coin protocol is a bit in flux right now, so this would be something to look at in six months or so.
I'll read more into how the new colored coin spec addresses originations, and also what mechanism is used to protect colored coin outputs from accidental redemption by normal wallets. Also I'm a big fan of brainwallet passphrases, so if using them presents difficulties, that would be a problem.
All this stuff is very new, so we'll see what happens....