How to count cell but not including duplicates in a row?

Hello, I was wondering how would I set up a formula where it would count a range of cells but avoiding duplicates in a row?

Red
Red
Red
Blue
Blue
Blue
Red
Red
Red
Yellow
Yellow

So an example would be, this would be 4 counts. It would avoid duplicates but only if it in a row like that.
Thank you

See if the following formula works for you:

=SUMPRODUCT(--(A1:A11<>A2:A12))