Although I respect this theme, I wouldn't go so far to make the realists seem so colorless, because the realist simply are seeing things for what they are, thus it would just be a normal earth. Also, I wouldn't label the colorful ones as artists, because plenty of artists are idealists or realists. However, i see where you are coming from when you say artist and so i cannot hold that against this piece. Over all, i like it, its a good idea to express these themes the way you did and i cannot take off you for simply having a different opinion as me.
Hnnnn... I use to be an idealist artist. And, as and idealist, I think the world is "divided" by more than 2 sides, but it is divided by multiple points of view. And those several points of view make the world look like the way the artists see the world.