There's Winstyle & Windowblinds but they're not free (although you can evaluate them) but I found them quite difficult & user-unfriendly (and I've used reshacker to customize most things!).
Then I found out about
UXpatcher which enables you to use themes created by other people with Winstyle (& others) without actually buying the software.
You will find thousands of style themes online, especially
here.
If you need any help let me know...