pie chart error when color parameter specifies more colors than number of data series

I'm running Confluence 3.5.13. I have a pie chart which graphs a dynamic set of data, which contains up to 4 data series. The color parameter specifies four colour values. When the dataset includes fewer than 4 data series the macro throws a "java.lang.ClassCastException" error.

The error can be reproduced using this wiki markup:

{chart:type=pie|dataOrientation=vertical|colors=maroon,blue,yellow,cyan}
|| Priority || Num Defects ||
| 2 | 1 |
| 3 | 1 |{chart}

The problem also exists on Confluence 4.3.3, the error shows as "java.lang.String cannot be cast to java.lang.Integer"

Resolution

Ensure the number of colours listed matches the number of columns of data.