Basic Trope: a location that is bright or full of color.
Straight: On their journey the heroes enter a rainbow desert.
Exaggerated: Everywhere has colors so eye-jarringly bright, with colors of all kinds.
Downplayed: A forest has every leaf unrealistically green (or orange/red/yellow in fall), but everything else looks normal.
Justified: The brightly colored area is tropical.
Inverted: The characters are multi-colored, but the environment is gray.
Subverted: A character goes through a rainbow portal, into... a grey world.
Double Subverted: ...except only that one spot was grey; everywhere else is still brilliantly colored.
Parodied: Characters regularly go blind from looking at the scenery.
Zig Zagged: Alice goes through a technicolor portal, into a brightly colored world. But she realizes she's wearing colored goggles! When she takes them off, everything seems dull... for a few moments, until her eyes adjust, and she realized that everything is still more colorfull than real life. Then she gets chased a few hundred feet by an Attack of the 50-Foot Whatever, and realizes that only that one spot is technicolor. But she liked the colors so much that she decides to get out a paint bucket and start painting the rest of the world!
Averted: The environments have very few colors.
"This show is for kids. Make it colorful!"
The creators, executives, artists, or what have you want to give the setting a fun and out-going feel to it.
Lampshaded: "This place looks just like my crayon box."
Invoked: The heroes grab some paint and start painting everything.
Exploited: "Oh, there's an enemy! I can tell because it's brown!"
Defied: Any time a children's show uses a normal/dim color palette.