Emily asks, "Please could you advise the formular solution for counting the number of cells that have a particular backgorund colour (i.e. these cells contain some data however the colour is what's important in order to count them).
"Logically I feel it should follow a standard formular i.e.
CountIF(A01:A55,"backgroundcolour=red")
I believe the colour red should be identified by the number 3 (according the the help file)
I need to know how to code the background cell colour i.e. colorfill?, backgroundcolour?, interior.color?...???

Emily - if only it were that easy. You need to have a User Defined Function in VBA. Below is the code for the function. You need to enter this in a new code module in the workbook. If you are unfamiliar with VBA, read this page.

Once you have the code entered, you can use this formula:
=countcolor(A1:A99,D2)
Where D2 has the background format that you want to count.

Here is the code:

Function CountColor(Rng As Range, RngColor As Range) As Integer

    Dim Cll As Range

    Dim Clr As Long

    Clr = RngColor.Range("A1").Interior.Color

    For Each Cll In Rng

        If Cll.Interior.Color = Clr Then

            CountColor = CountColor + 1

        End If

    Next Cll

End Function