Locking text in cells but not the ability to change colour of cells

[SStrat1]

Hi
I have a spreadsheet where I can change the colour of a cell by clicking the mouse, I also have text in many of the cells.
What I need to do is protect (lock) the text so that no one can change the text in any of the cells, but I still want to be able to change the colour of the cells by clicking the mouse in that cell.

Any ideas would be greatly appreciated.

Thanks

Steve