I think its worth it. in my case, a colo ele stone, a lv 140 pure elemental stone has about 285 base elemental intensity.
a lv 140 Colo orb/ staff will give about +31 base intensity. Which is a little bit over 10% in extra base damage overall, as in base damage thats multiplied by max and min magic damage and put through the crit damage multipliers as well.
If you want more raw damage, it's a pretty decent boost. If you're using a dual element stone which has less base intensity for both elements, the colo's bonus is even more significant.
Make life what you want it to be.