Gene, I don't know the answer to your question but the following may help.
1. Click in the Chart / Chart Tools / Design contextual tab / Chart Styles
In here these is a whole variety of different colours to choose from.
2. The other thing that you might consider is Page Layout / Themes group /
click in the Colors drop down and choose what you want from here.
You can also set up your own Theme Colors in here by clicking:-
Create New Theme Colors . . .
3. Finally you might like to consider Page Layout / Themes group / click on
the drop down arrow beneath the word Themes and then select a Theme of your
choice. This will affect the colours in the Chart.
If my comments have helped please hit Yes.
Thanks.