How do the Gradient Stop Color (click to cancel) and Last Color (click to set) options work?

Question

Adobe Illustrator

What does the Gradient Stop Color (click to cancel) option signal? When does it appear.
When does the Last Color (click to set) option appear?

Answer 1

With Last color, everything is simple - the chandelier remembers the last color that you adjusted in one way or another, and offers you to use it (in the case of the situation in the screenshot, the gradient fill will be replaced).
Gradient stop color - just one of the stretch colors, but don't know what will happen after clicking to cancel)