Can no longer change colors

[1325park]

For some reason, I can no longer change colors like I normally do . I go to Enhance>change color and everything is greyed out except defringe layer.  Any suggustions would be greatly appreciated, thnk you !

[MichelBParis]

For some reason, I can no longer change colors like I normally do . I go to Enhance>change color and everything is greyed out except defringe layer.  Any suggustions would be greatly appreciated, thnk you !

By @1325park

Let me guess: you are trying to edit a greyscale photo?

What happens if you convert it to RGB via image > mode?