Blumies are imaginary characters. We guess they where made out some sort of liquid... Maybe it's water? They actually never told us what they're made out of and from which planet they came, all we found out so far is their names and things they are interested in!
Looks like Blumies goals and interests are strongly depended on their skin colors.
Some enjoy creating art, others explore the world they arrived to... There's even Blumies that are in charge of creating events! We haven't figured out yet how many colors there's in total, they're probably hiding somewhere.