This theme is inspired by the great Vimix theme from vinceliuice, that you find here : https://www.gnome-look.org/p/1013698/. It also has a red based variant, available here : https://www.pling.com/p/1319029/
I prefer the flat dark themes, but many have identical foreground and backdrop colors, what makes it difficult to distinguish between open windows. Most themes I found are also either too rich, or too poor in colors. I also missed a little more stylish title bars in the windows.
I added a little bit of a blueish background and hover colors to some items, to make them more stylish, added a gradient to the title bars, and refurbished Nemo's appearance. The menus also got a new face. When you open several windows, the one on top has a lighter background color, what makes it easy to distinguish between them.
The theme has been tested mostly on Ubuntu Budgie, but also works in Gnome.