Highlighting Scatter Points
Here's a technique that everyone should be using – Everyone. Instead of using an oval for highlighting scatter points, consider using a rounded-edge rectangle with the edges rounded to the max.
Doesn't that look nice? Ovals can get very fat in the middle and skinny at the ends. Sometimes they work and sometimes they really don't. This AutoShape always works.
Just move the yellow adjustment handle all the way to the right and the ends will resemble a capsule. Then remove line, adjust fill color, position over the group of sprites, adjust size, and move to back. You're done.