New Rainbow only Titan idea

At least i think this is new as I have not seen a Titan of this nature yet.

We have regular titans and rare titans, both at various levels. some do damage only, some do damage plus an effect (-defense, -accuracy etc). Rares do the same plus reflect color.

Here is my idea…

What about a Titan where you MUST use rainbow team to attack? it would be fun and another way of mixing it up a little bit. Could make them be possible at any level and either rare or non-rare? of course the Titan health may need adjusted accordingly??

Thoughts everyone? Is it a good idea or a bad idea?

Regards,
Zoob