1. I do not know if this is possible directly in NPrinting/PPT but you can change total to last row in Chart properties / Presentation.
2. You need to use background color of expressions and dimensions and use the Dimensionality() to find out at which level you are. Note - use Dimension limits Total to get background color in dimensions, the expression total does not honor it.
So expression like this will give you red for Total, green for subtotals and blue for normal rows.
Pick(Dimensionality() + 1, red(), green(), blue())