Grayish brown and Light brown

Grayish brown noun - A color or pigment varying around a light grey-brown color.

Light brown and grayish brown are semantically related. In some cases you can use "Light brown" instead a noun phrase "Grayish brown".

Light brown noun - A brown that is light but unsaturated.

Grayish brown and light brown are semantically related. Sometimes you can replace phrase "Grayish brown" with "Light brown", this phrases are similar.