No use trying. You can never set a single theme across all areas of the phone (home screen, app drawer, settings, menus, etc.) because Android lacks UI design and UX design.
The only way you could make your phone look right is by either installing Windows (for phones) on it or iOS. The first one uses a minimalistic theme across all areas of the OS, while the other one uses a more colorful and childish design, but still the same theme on all screens.
But Android... Android is so fragmented that you cannot get ALL your icons to follow the same style, text is displayed in a multitude of sizes and fonts while missing alignments, colors and effects look like they were picked at random, etc.
All in all, Android is just a platform for using a fuckton of apps (most of which are useless anyway) and you can just accept that it will never look as good and streamlined as Windows or iOS.
