I have a better idea for the Dark Auras in World R4
Rather than the key count of their counterpart, the aura effect simply checks the key count of its corresponding color, regardless of their countpart.
When you have neither 5 green keys and 5 forest keys, you do not have either of their effects.
When you have 5 green keys, you have the green aura effect, and when you have 5 forest keys, you have the dark green effect.
When you have both 5 green keys and 5 forest keys, they cancels out and like you have neither of them.