Need a macro for Excel 2007

A very large spreadsheet has 89 columns (I know - this should be in Access),
and filtering is used to analyze. Sometimes users will filter once, then
filter a second or third time, and get lost as to which columns they filtered
on. Is there a way to know which column is the last filter? Would a
solution be to change font color of the header cell of the last column
filtered - to know how to retrace and undo their filters? What would the
code be and where would it be put - in the workbook/worksheet or in
"Personal?"