I propose to change the rules of the pool so that it isn't totally useless.
Hair color isn't the point at all of any of those Wriggle x Yuuka images.
1. Either only two of the current members (no non-green hair).
2. Or at least three of the members, even if there are non-green haired girls present.
The rules should be like the ones of pool #2353 Touhou - Stages Gathering.
Just read "stage" as "hair color".
If it adopts the second rule of that pool, it can be extended to other hair colors.
It can also be used for all copyrights.
Updated by DschingisKhan