How to highlight cell based on list on another worksheet

I have a work sheet (List of things to keep)with columns containing two separate lists, one column is Model Names, the other is Part Numbers.  Neither of these two lists is related to each other.  On another worksheet (scanning sheet) in the same workbook, I have a column that I want to be able to enter data into, and if the contents of a cell in that column (in the scanning sheet) match anything in either of the two lists (in the keep list)  I want that cell to highlight.  I've tried numerous options based off of search results in the web.  Conditional formatting doesn't quite seem to work for some reason.  Any ideas if this is possible?