Stop duplicate data

[razlan]

I have a list of data in cells B1, B2, B3, B4, B5.

For example :-
B1 - red
B2 - blue
B3 - green
B4 - white
B5 - yellow

How do I stop users from repeating any of this 'color' in cell B6?
Meaning .... no duplication of data.

Thank you.

 

[T. Valko]

Try this...

Select cell B6
Goto Data>Validation
Allow:Custom
Formula:

=COUNTIF(B1:B5,B6)=0

OK