Colour formatting negative values

Hi,

I am having dificulty formatting numbers in my P&L report,

See the screenshot below.

I want negative values to display in red,  which I have achieved with conditional formatting.  However, when I apply a format string to certain fields it seems to override the conditional formatting and display only in black.  In the example below ITDA has no formatting whereas NPBT and Net Margin have formatting to remove the pence and show as a percentage respectively.

How can I get the correct number formatting as wel as the colour formatting.  (much simpler in Excel!)

(The values in the table are measures selected with a Switch command, just in case that makes a diference)

Thanks