How can I change the active thumbnail color in the Blockshop Theme?

Store Design
1

Hello all,

I am in the process of altering how thumbnails appear on the product page and have successfully changed the full images to dots but cannot figure out how to set it so the active thumbnail is a different color than the others.

example url:

https://thesunshopp.com/collections/mens-sunglasses/products/costa-del-mar-rincon-179-osgp-matte-smoke-crystal-fade-polarized-gray-silver-mirror-580p

Thanks