how to remove color of highligthed cells

Greetings,
I have highlighted duplicate values in two columns of data. I made the following process
I selected two separate columns,
on Home menu i hit "additional formatting" and chose "highlight cells rule" and finally "duplicate values". similar values in both columns were colored with red. Now I want to remove the red color. When I use normal way (clicking on "no fill") it doesn't work.
Could you please help me.
Thank you

I do not have the 2003 version so im not 100% sure where this is located but most likely under additional formatting there should be a button that says clear rules or manage rules (thats what it is called in 2007+ version) this will remove the duplicate values highlighting.

on 2003 version there is no additional formatting but conditional formatting