In Photoshop, what does the * to the right of the colour mode mean?

Question

In the title bar of an image, what does the * to the right of the image mode mean?

At first I thought it meant there were unsaved changes, but it turns out I get a second * in that scenario:

Answer 1

The * means there's a colour profile mismatch.

This article, while quite old, explains colour profiles and how you can remove the * by resolving the mismatched colour profile.