Khaki and Olive brown

Khaki noun - A sturdy twilled cloth of a yellowish brown color used especially for military uniforms.

Olive brown and khaki are semantically related In some cases you can replace phrase "Olive brown" with "Khaki", this terms are similar.

Olive brown noun - A shade of brown tinged with green.

Khaki and olive brown are semantically related in light brown topic. You can use "Khaki" instead a noun phrase "Olive brown".