I have a couple of pea green/ olive frogs that have never turned the Kelly green shade, so it's probable they won't. I don't know for certain, but I suspect that Kelly green is more common in the Aussie genepool so frogs with more of those genes are more likely to be that color.

You'll probably have frogs of different shades at some point considering the way they change colors. At the very least you can brighten up your frogs by experimenting with the light in the tank. It won't change their colors, but it will show them off to their best advantage.