Animated Cartoon Can't Think of What it is please Help!?

I have a friend from Argentina who's trying to figure out the name of a cartoon he believes is from the U.S. I have never heard of it. Here's the description. He says there are some gnome like creatures who live underground that have a factory of colors...and they have tubes from the different work stations the go up towards the service. The point is they battle this cloud..who he believes is a representation of winter. Does this ring any bells with anyone. At first I thought it was Fraggle Rock, but it's completely animated. Not the smurfs or gummy bears or anything else I could think of.