Is the idea of color coins/open assets still alive? Are there any interesting projects ahead on this way?
There are at least 5 different colored coins implementations on bitcoin that I'm aware of. The ones in active development include:


Colu - They recently showed how their implementation can be used with the lightning network. https://www.colu.com/
Chromaway - They've been running a lot of pilots with various banks and whatnot. http://chromaway.com/


There's also a slack channel for colored coins as well, which you can see here: http://coloredcoins.org/

So no, it's not dead and there's still plenty of development going on.