Formating the show values in a crosstab chart

[Ann]

Hi All

I have a combination chart, showing sales numbers on stacked bars, total sales represented using a line  and Goal value using a line.

show values is enabled in my chart.

But user wanted to see this values in different font color.

Values on stacked bars should be displayed in white, and the values for trend lines should be seen in black.

Any clue how to implement this?