Color rows based on Value above

I'm sorry; I'm down with some type of sinus sickness, so my brain isn't working right, otherwise I'm sure I could figure this out. I want to color each row in my spreadsheet if the value in column C matches the value of column C above or below it. I know how to color the rows, but I'm drawing a blank on how I'd set up the

IF A1=A2
'Run my code

On both A1 and A2

We're talking about 14000 lines, and in that range there are 6000 unique values.

Thanks in advance for any help on this.