Compare Two Fields and Highlight Cell if Different.

I need a way to detect a cell change and then have the cell background color change. Here is a layout/description of the issue:

WB1 - this will be my main data file that updates WB2. Parts of the data within WB1 can change on daily basis. Therefore, I plan to simply "overwrite" the existing WB1 file with a new one each day when I get them. (example: Data.xls)
Sheet1 - this has all of my rows of data including a unique identifier (Account #) that will allow me to tie my WB2 to WB1.
Cell A1 - Account Number
Cell B2 - Notes

WB2 - this will be my Master file that I will work from on a daily basis. My intention here is to have the WB1 (Data.xls) document to update cell A2 on WB2 with a simple formula of (WB2!B1 = [Data.xlsx]Sheet1!B1). This works great to make sure that all of my notes from the updated WB! (data.xls) get updated into my WB2 file using a VLOOKUP on A1 back to the data.xls file. However, my goal is to have the cell color change for only the notes that actually changed.

Example: WB2/B2 originally said, "This is my note." But when I replace the data.xls file, the note (B2 in data.xls) now reads, "This is my updated note". Therefore, WB2 would be updated with this updated note and my goal would be that the system would detect that the "contents" of the note are different than what it was before it updated the field and would update the data and change the cell color.

I have tried to use "EXACT" as part of my formula, but the data updates have already occured and therefore, the comparison is always TRUE.

Can anyone tell me and provide me a sample code of how I can achieve this?

I appreciate your assistance with this question and I hope that I can return the favor one day as well.

Sincerely,
Doug