Prevent Pasting
 

I have a spreadsheet with multiple tabs, each of which has numerous cells
formatted with an interior color index of 36. Is there a way to write code
that would prevent anyone from pasting anything into these specific cells? I
would need to be able to 'deactivate' this code by editing it and changing to
'off' or something like that, then when I want to activate it again, edit
again and change to 'on'. I do not want to use worksheet protection to do
this. Thanks for any help that can be provided.