VGB/TrixR4Kidz,
That's correct, I was searching for cards specifically for the maindeck. If green were added as a tertiary color alongside red & white, would any green cards make it into the maindeck?
Holistic Wisdom - I totally love this card, but I've never been able to get it to 'work' in a deck. If only it was 1UU!
Bind, Oxidize, Berserk, Drop of Honey, Seedtime, Root Maze, Krosan Reclamation - I'm not sure these would fit the theme of 5CC, although I'm certainly willing to entertain the possibility. Root Maze is very interesting as a sideboard card vs combo.
Pernicious Deed - I hadn't thought about this one, but it is arguably the most flexible Disk effect. And with all the cheap permanents running around the meta, this card is more valuable every day. (I notice WTF/r is using it too)
Matt,
You are correct, green is much more valuable in standard than it was before they began balancing the color wheel. But the topic of the thread is to entertain the idea of adding green to 5CC and see which cards 'shake out' as being worthy. I guess I shouldn't poke at WotC for not adding control to green..

VGB,
1) Completely valid point, and the major reason I don't think Living Wish is vialble in a 'real' 5CC build.
2) I would disagree. Cunning Wish was touted as being too slow when it was first introduced, but I rarely have trouble finding drain-mana or a sol-ring to fill up the 2U, not to mention the spell that it fetches. I'll stick out my neck here and say that most of the situations you need one of your sideboarded options, Living Wish will provide adequate speed for; Exalted Angel, FTK, Mox Monkey, Plaguebearer, Stripmine, LoA, fetchland..
3) Yes, exactly what I was reffering to when I mentioned deck compression. Let's say you run 4x Living Wish (go all out!) replacing 1x Mox Monkey, 2x Exalted Angel, and Stripmine. Now you can drop LoA(it's sided), and the other Exalted Angel + Mox Monkey, freeing up 3 slots maindeck. I should mention that my 4CC build runs 3x Exalted, 2x Mox Monkey.
More interestingly.. what if you ran 2x Cunning, 2x Living, and one win condition main. That's 2 cards (replacing 1x Cunning, 1x Mox Monkey), freeing up 6 slots (2x Exalted Angel, 2x Mox Monkey, 1x Stripmine, 1x LoA). That's a lot of slots!
You're safe in the end-game, since you still have an Exalted Angel maindeck, but you put situationally relevent cards in the sideboard (1x Exalted, 1x Mox Monkey, 1x Stripmine, 1x LoA, 1x Fetch, 1x FTK).
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Thanks for entertaining this thread, I hope you've had fun with it too. So far, the consensus seems to be:
Worthy Green cards for hypothetical 5CC (and why we don't use them):
Regrowth - Would probably be used in 5CC.
Living Wish - Interesting, but not realistic due to sideboard squeezing.
Pernicious Deed - Color cost too high.
Artifact Mutation - Color cost too high.
Hollistic Wisdom - Color cost too high.
Did I miss any?
--Bryan