Limiting Styles to a usergroup?

[Spaz21]

I'm in the process of making changes to the forum, navbar, colors, etc. I want a select group on my forum to be able to access this new style so they can access new features through the navbar to test stuff.

Could I create a style called "test" for example which could be a duplicate of the current style but restrict access to the testing theme to a usergroup i specify?

I thought i remembered seeing this option somewhere but i cant seem to find it now.

Thanks