Custom quiz review assets

Hi there,

When I add a quiz slide (built-in, not custom), on the quiz review I see some icons, like correct answer, incorrect, etc.
As I wanted to customise these icons, I did and I replaced them in the QuizReviewAssets folder. Everything works fine. 

My question is, how to have different icons for different projects. Can I keep all of them in the Assets folder and then select from a drop-down menu? Or how to manage them?

Thanks!