I always change the default color that Revit uses for selected elements. I use Red.
The default setting is the same blue that is assigned to Pre-selection. I don't recall when that changed but somewhere in the fog of time it used to be assigned to red. I happen to like the visual confirmation, the difference between what is highlighted and what is selected. To each their own.
If you want to change it too: Application menu (Big R) > Options > Graphics page