Window Manage Problem

Opening Settings>WindowManager-Style. … Theme changes are not reflected on the screen.
I am currently stuck with very small window buttons and a small margin.
Any ideas?

I should have added that this is a fresh install.

My mistake … it appears that the changes are taking place but only after the Setting Manager is closed. I was under the impression that the changes were diectly shown brfore closing the S.M. was closd.