Menu element multiple select customize

Currently, it seems when a menu elements is in multiple selection mode, when selecting any entry, it highlights said entry in a real thin, blue boarder. 

Would it be possible to add in a feature to customize the effect of when an entry is selected inside of the menu element? Maybe change the color of the boarder around the selection, the size of the boarder, or maybe even a way to highlight the entire entry in a different color. 

Depending on the color or the scene/menu elements, can sometimes be hard to see which entry is selected and which isn't.