I think Emerald Green is much more versatile because I think it's the kind of green that goes well more with other colours like golds, neutrals, browns, etc. Although if you have Humid e/s, it's pretty close to it as well. Kelly Green on the other hand, is much brighter, much more suitable for daytime looks and it's a much more fun colour. I don't think there's a perm e/s that's close to it.