Taken from that link you gave us:
. Galanctonotus, Leucomelas are hardy, group-friendly frogs.
Honestly, a mix tank of two different morphs of frogs is a cool idea in the aesthetic aspect. Just don't let them mate. Easy as that. Interbreeding is just a sensitive black and white topic here on Dendroboard. But interbreeding is different than simply keeping a couple different types of frogs together in a tank to make it look more "natural" or "varied." No interbreeding though whatever you do please! I recommend getting a group of one type just to avoid the flamers here