Cannot right click to fill on images

[defaultac1uvlhix8pe]

I am a basic user of photoshop and last week I sent some jpgs asked to make changes to them.

Previously if I wanted to alter or edit, for example reverse the colours or change the background, I could just right click on the colour and (using a letter for example) it would select the shape of the letter and I could select fill to put in a new colour.

Suddenly today when I open up photoshop and right click I cannot get anything selected.  

I have tried every tool in the options but can't find the right one.  

I know this is most probably something simple and stupid that I am missing but please advise.

[Trevor.Dennis]

I think you must be talking about Color Range.  Are you seeing that option