I think simpler (though without a script) assuming the Status
column is ColumnS.
Select ColumnS and clear formatting from it. Select entire range to be formatted and Format, Conditional formatting..., Format cells if... Custom formula is
and:
=and($S1<>"",search("Complete",$S1)>0)
with fill of choice and Done.
This is not case sensitive (change search
to find
for that) and will highlight a row where ColumnS contains the likes of Now complete
(though also Not yet complete
).