askan,
I like your idea. Right now it could probably be modded in some way to get close (but not quite) what you want.
1. Make the starting Colo Tech a racial trait (don't forget to take one).
2. Normal Colo Tech can still be researched. In order not to get it too easily by ruins, it could be "hidden" further down the tech tree. Either by adding lots of levels of Colo Tech (1-9 gives you nothing, but 10 will finally give you the component) or by adding lots of requirements for it (Construction, Physics, Chemisty, Planet Engineering, add a few levels like Geology, Meteorology, Oceanography (Hmm, how come water planets are not in the game?), you get the idea). If you find this tech in ruins it will help you, but doesn't give you the component right away.
Of course, this Colo Tech gained by research could still be traded, but I guess this would be okay.
Another easy solution : Turn off ruins and trading altogether
.
Just an idea (and not fully thought out),
Rollo