Is This Possible?

Hi, I’m running my wordpress with the complexity 2 theme and wanted to set a different theme on a part of my site. The complexity theme has loads of different variations and I wanted to use one of the other colour/style options of complexity2 on a certain part o the site whilst maintaining the original style/colour throughout the rest of the site.

How can I do this?

The only thing I can think of is installing another version of wordpress and running that theme on that wordpress and connecting it to the main website but keeping the url of the main website. But I don’t know if that is possible.

My site is: https://sadaqallahul-azim.co.cc/