Conditional Formatting

Afternoon,

I'm attempting to create conditional formatting in which I ask excel to turn any cells in column BU blue if that string value (I usually work in SPSS so I may be mixing terms here) in that column is the same as, and red if it is different from, its corresponding row in BE. I am using the following formulas:

=$BU=$BE and =$BU<>$BE 

respectively. Once I've typed it in, however, I receive this error message: https://support.microsoft.com/en-us/office/how-to-avoid-broken-formulas-8309381d-33e8-42f6-b889-84ef6df1d586?ns=excel&version=90&syslcid=1033&uilcid=1033&appver=zxl900&helpid=xlmain11.chm196624&ui=en-us&rs=en-us&ad=us

Unfortunately, everywhere I turn on the internet is telling me that these are the formulas I'm supposed to use. Is this outdated information? Excel changes it to ="$BU=$BE" and ="$BU<>$BE" and nothing happens to my $BU:$BU column.

Any help or insight would be greatly appreciated.