In that case, you'll have to loop through the columns and do it
(and are you sure you want the back color to be black, or is it the DynamicForeColor you want?)

** grid.Init()
Local lcSource, loCol
lcSource=this.RecordSource
For Each loCol in this.Columns
  loCol.DynamicBackColor="IIf("+loCol.ControlSource+"<0, RGB(255,0,0), RGB(0,0,0))"
Next

>Sorry Metin, this can't work.
>The grid has 12 columns for the 12 months of the year. VALUE is not a field. Each coloumn in the grid represents a diffrent field, so when I run it an error message appears saying: "Expression is invalid. Use a valid expression for DYNAMICBACKCOLOR"
>Maybe I didn't make myself clear enough.