I guess I should have specified that I meant you would probably have to mod the exp module also. For the money/effort I would just get a RGB modified Atari 2600.
For RGB out on the coleco you just need to feed the amped signals through a LMH1251 something like this:
Very WIP and probably has alot of incorrect stuff atm. It only now has occurred to me to just use luma for sync and not bother with the lm1881 still if I made a board I would still have the option.
I am too busy atm to play around more for now. Anyway it looked like all the signals were compatible with my TV unamped #shrug. I would still use the amp to normalize the output but you could probably get away with some 220uf caps feeding the signals directly into the LMH1251 for RGB (or directly out to your TV for component). I just need the amp to split the signal so I can mix for composite/S-video as well.
The video divider (in the linked schematic) would just be a THS7374 or a THS7360.
If you pull from the RF box make sure not to use the 12v power rail unless you are going to step it down with a 7805 id just pull 5v from someplace else.
C66 and C67 are under the RF modulator (I desoldered mine) you should be able to pull video off the top pins similar to the S-video mod and scratch off that one trace, id still wager that you would get better video with the RF removed. .
Edited by the_crayon_king, Sun Nov 20, 2016 2:27 AM.