Adwaita Color Variants is a theme pack containing Adwaita, the default GNOME theme, in 12 colors.
The pack includes the latest Adwaita refresh for GNOME 3.36 for which only the accent color was changed, in the following colors: gray, red, orange, yellow, grass, green, teal, cyan, indigo, violet, magenta and pink.
All these color variants are available for both Adwaita light and Adwaita dark, and they support GTK3, GTK2, and GNOME Shell (so you'll also get an Adwaita GNOME Shell theme in the color of your choice, in both light and dark variants). The pack does not contain a matching icon theme, at least for now.
There's also an Adwaita Color Variants script that can generate Adwaita using the 12 colors I mentioned above, it can install the themes, generate a compressed archive, etc.
These are a few screenshots of Adwaita Color Variants GTK3 themes: