Why not create customised Charts that deliver your message using images rather than solid colours or patterns.
Create your chart
Select the element you want to change and right-click the mouse.
Choose Format Data Series,
Fill
Select Picture or texture fill.
Select the image you want to use from your folder .
Select either stacked or stretched
Click Close.
(http://reallyusefultraininganddevelopment.ie/wp-content/uploads/2011/11/image_thumb14.png)
Note: You have a choice, you can add a single image to an entire data series, or you can click a single bar or column and use Format Data Point to add a different image to each column or bar.
Source: Really Useful Website