Highlighter markup during presentation - In the newer versions of PowerPoint, the highlighter markers simply overwrite each other, with only the last color showing. In previous versions of PowerPoint (e.g. 2003), when highlighters overlapped they created a "blend" of colors. For example, highlighting an area with both yellow and blue created green. As a math teacher, this was extremely useful in showing where areas overlapped. Could this feature be reintroduced in an update? Thank you.