I didn't see how to change the symbol -- but i did see where to change the selection color ... which i was looking for when i found your post ...
Have you found a solution? I'm tinkering with selections and data views today to see if i can get this idea in my head to work and i'm wondering if maybe a combination of a second layer in the map with the selection symbology you want could possibly work ... using a framework action to then filter that layer ... trick is how to get it to not show when nothing is selected and then draw when something is selected ... the empty views, haven't tinkered with them but maybe?
seems a like a neat idea!