Conditional Formatting when cells are from certain sheets

Ok In the attached document there are 3 sheets:

• Sheet 1 (Combined)
• Sheet 2 (Data Text 1)
• Sheet 3 (Data Text 2)

Sheet 1 combines the data in sheet 2 and sheet 3 by referencing the cells in those sheets. What I want to do is conditionally format the cells on sheet 1 (combined) red when the data referenced is from Sheet 2 (Data Text 1) and blue when the data is referenced from Sheet 3 (Data Text 2). I have tried everything and I can't get it to work. What I don't want to do is create additional columns (e.g. create a new column in column b in Sheet 2 that says Data Text 1 and the same for Sheet 3 and then on sheet 1 check if the text in column b ="Data Text 1". Is it possible to conditionally format a cell based on its formula? Then I could get it to work as I could just format the cell if the formula of the cell =DataText1!A2...etc.etc. I am open to suggestions and ideas that might be outside the box. Thank you so much!!!

Thank you so much Marcol, you are a life saver this is so helpful. I would have never have been able to come up with this on my own it is completely beyond me! THANK YOU!