FBX models imported to Unity have washed out colors

Unity’s default lighting conditions are not the best-looking, so some work is required to get your scene looking good.

If you’re using the standard shader, make sure you project is set to linear color space, not gamma.

Just like in the real world, the color that an object appears depends very much on the strength and color of the light that is shining on it, so experiment with that.

In addition to just your directional light, also look at the environment lighting tab in the lighting window.

The environmental lighting is basically just a flat value that gets added to everything in the scene. Too much will make your scene look washed-out. Not enough will make your shadows look too dark (Like you’re in outer space).

If your scene is set to used baked or mixed lighting then you need to “generate lighting” for static objects to look correct.

Try adding post processing, especially ACES tone mapping.