I want to use three colours to highlight a spreadsheet, red for numbers less
than -1, amber for number between -1 and 0, and green for numbers greater
than 0 which I can do no problem. Each cell that I am colour formatting has
the formula (or similar):
=IF(G2="","",IF(M2="","",M2-G2))

However the blank cells are also being coloured in green when I want them to
remain white. Any ideas?