Make your own theme.
I will try to tell you the steps to add a new theme and along the way you will learn how my dotfiles work, it is nothing out of this world but if you do not have experience it can be a hassle to understand it the first time.
At this point I also do not intend to teach you how each configurable option of polybar, bspwm, etc works.
Polybar has a fantastic wiki, eww its documentation is a bit difficult to understand if you don't have prior knowledge, bspwm, well its documentation has a lot to be desired but you won't need it much either.
You will be able to have a new theme, but with the styles and designs that already exist in my dotfiles (at least rofi menus and eww). Of course, if you want to create a new rofi menu, or a new widget, you will have to read its documentation, learn some CSS, bash, yuck, etc.
The first thing will be to copy the folder of some theme, I always copy the "emilia" folder as a starting point. Copy and paste it into the same rices directory and rename it whatever you want, in this case I will call it like the new theme I am making "daniela".
Now if you press Alt + Space bar. You'll notice that you now have a new theme listed in the theme selector, with the name Daniela but it still looks the same as Emilia.
Under construction, will be back soon, or not to soon.. but will back... :)