I have a spreadsheet which I require the numbers 1-300 to be green, 301-800
to be orange and anything 801 and in excess to be red.

The only way I seem to be able to do this is by establishing a sheet, which
I hide within my worksheet, listing consecutive numbers in 3 separate columns
and naming green, orange and red and using the formula is aspect of
conditional formatting along with a countif formula.

Is there an easier way of doing this, as there are occasions when the ranges
are changed?

Many thanks for any help offered.