I get what you are saying, but note that the amount would NOT be random. Red would vary level-by level, but blue and green would have the EXACT same amount in every level (which is what I'm doing with ep5, and will definitely be converting ep3 and ep4 to). 20 green and 10 blue.

If I edited ep1 and ep2 to have gems like the other episodes (and that's a big if), I would basically keep the purple gems in the same spot. They would just be changed to green or blue, and I'd add a few more gems, probably most of them in the same places, to round it out to 30. They generally wouldn't get mixed in with red gems either (I use red gems for normal areas, and green/blue for secrets and hard to reach spots). My reason for considering this change is consistency. I'm a bit obsessive when it comes to little differences in design and stuff like that. For example, I once updated the first few episodes just to change the height text appears at, so all the episodes are the same.

I find it interesting that people prefer purple gems. Is it the colour that matters? Or the fact that they are the only gems you can find in the level? (this is untrue btw because ep1 and ep2 DID include red gems, just not very many). Or is it because enemies don't randomly drop them?