Pretty sure the three resources you're referring to are the ones from the released screenshots:
Blue (main resource like minerals), pink (more limited, high tech resource like vespene) and bread (supply). Devs have said they're happy with how warcraft and starcraft's resources work but they are exploring having multiple ways of gathering them, like how AoE gives you many ways of earning food or gold with different pros and cons.
We know the resistance has a building called "therium refinery", but I assume therium = pink resource and infernals will likely also have a way of harvesting it.
There's also "anima" that the infernals are looking for on earth, but they haven't revealed whether that's just a lore thing or an actual resource.
But yeah, it's possible that creeping gives blue and pink money. Possible it gives some exotic other resource. Who knows.