Vlookup check - struggling with formula

In the attached spreadsheet I need a formula that will:

For every item in column A "Ref" in the "Summary" workbook
Check to see if the value is in either of the named ranges "Lookup1" or "Lookup2"
Then in Column A on the summary sheet put in conditional formatting that will color any value not in either list red.

I want to highlight any values on the Summary workbook not in either of the ranges. So in the example highlight 3 and 4 as they are in neither list.

I've been mucking about with the look-up formulas in columns B and C and have the logic to check of the value exists, but can't crack a conditional format formula to highlight any item not in either list.

Would appreciate some help on this one if possible please.

In the attached file I've defined the named ranges Lookup1 and Lookup2 on those sheets, then the conditional format formula is:

=COUNTIF(Lookup1,A2)+COUNTIF(Lookup2,A2)=0

to turn the background colour to red.

Hope this helps.

Pete

Just the ticket - many thanks for your assistance.