coloring like an artist vs. coloring like a scientist

When I taught kindergarten several years ago, I would find myself in a situation where I would be trying to get a kid to color things realistically, and feel awkward about stifling the child’s creativity.  I came up the idea of drawing like an artist vs. drawing like a scientist.

“An artist can color things the way she wants to.  Trees can be pink, and hair can be green.  Scientists, however, color things the way they really are.  Which way are you going to color your drawing?”

And then I get little choruses of “I’m going to color like an artist!” and “I’m going to color like a scientist!” and all is right with the world.