How can I format a cell to conditionally show a number in red font if it's negative?

You cannot (currently) easily. Conditional formatting of the type you are considering is a feature of Excel which the financial reporter does not (currently) support.

Support may have a suggested work around.

Hi Steve,

If you format a column for font or color, this will override whatever conditional formatting may be generated by the .RowFormat process. So if you specifically format all columns with black font except for the column(s) that you want to appear as red, then it will appear that only cells in the unformatted column(s) will be red.

But what if I want to conditionally format multiple columns, and each has its own test? And what if I want the default color for various columns to be different?

I will send you a sample spec.

Steve

Sorry. You can't always get what you want. (With apologies to the Rolling Stones).