First, off I’d like to explain why that is happening, it is because you have chosen the Integrity dark design, so with that, you get the default elements as light color (e.g. the tags) to balance the contrast.
Now back to the issue, I would like to advise first to set the Integrity design to Light and see if that does more good than bad. If it’s the latter then add the custom CSS code provided by Prakash above to solve the tags issue (minus the
.tag-content selector though).
However, because you’re using Integrity dark design you might encounter this same issue with different default elements, like the heading, subheading, and other unforeseen elements and the only solution is to use custom CSS. I hope the Integrity design Light will work just fine though so you’re not going to need custom CSS.
Please note that the caching plugin/feature you’re using is very persistent (even to login user), always Purge cache when you do edit so you can see the changes immediately.