Hi Gunnar.

The problem you are having is that the DynamicBackColor is evanuated in the context of the Grid, not the Column. There for "This" refers to the Grid, not the column you are looking at. If you reference the Field Name in the expression instead of This.ControlSource it should work fine. If you are trying to get each column to display a color based not on the record, bot on only the field in the column then something like this should work -

Local loColumn
For each loColumn in This.Columns
If Type(loColumn.ControlSource) $ "NFIBY"
loColumn.DynamicBackColor = "iif("+ loColumn.ControlSource +" < 0, Rgb(255,0,0), Rgb(255,255,255))"
EndIf
EndFor
loColumn = .NULL.

Ian Simcock.