How to Sum cells that have been conditionally formatted

[kbaz555]

Can anyone please explain in layman's terms how to sum a column that has been conditionally formatted.

On the attached spreadsheet Sheet 1 D6:L18 has been conditionally formatted (green text and green font if certain customers appear in column A) - the data acquired by vlookup from a separate workbook. I would like a formula in row 31 to sum only the figures in black font - if at all possible!

I've had a look at cpearson.com about colour functions but it's way over my head.

Any help would be appreciated.