What colours have 4 letters?

4-Lettered colors. (In alphabetic order):

Aqua

Blue

Buff

Corn

Cyan

Flax

Gold

Gray/Grey

Jade

Lava

Lime

Mint

Navy

Plum

Roan

Rose

Ruby

Rust

Sand

Teal

Yale (Blue)

Remember, colors are nouns and adjectives. For example, if you say "kiwi", that is a fruit, which is a noun, and has a color. So you could say a "kiwi-colored shirt".