You may not like the 2/3 red O in the top corner, but wait until you upgrade to Windows 10. Then you'll get a (full) black O.
It's amazing how M$ spent 15 years making the Windows GUI as intuitive and pretty as they were able to, and then they just thrashed the whole idea in favour of flat colours. I cannot count the number of times I've closed the wrong window in Win8/8.1/10, just because some idiot at M$ decided that a simple black-on-white X is easier than a white-on-red one. Note that the black-on-white X is the same as the one that is used to close a file within an application. Now it serves for everything - such is "progress". And I'm forever using the wrong scroll bar.