When I started this project I had Debian 10 installed so I had to download Debian 11 gnome and start with a fresh installation.
Here's the link to the Debian 11 download page:
This image of Debian 11 already has the non-free firmware so you won't have to fight with drivers after your install.
First download the Sweet-Rainbow.tarxz and extract it in the directory of your choice. The Sweet-Rainbow.tarxz is at the bottom of the list under Download on this page.
Once you extract the Sweet-Rainbow package you will have to move it in order to select it in Tweaks.
Go to the directory that the Sweet-Rainbow package is in like so.
cd (Name of directory)
Then type ls to list what is in the directory. Next move the Sweet-Rainbow folder to ~/.local/share/icons/ with root privileges. Like so:
sudo mv Sweet-folders ~/.local/share/icons/ and press Enter.
Type in your password and press Enter again.
Now open your Tweaks application and go to Icons and you should see Sweet Rainbow in the drop down list. Select Sweet Rainbow and it will change all of your folders to the Sweet Rainbow ones.
Here's a picture of mine:
As you can see all of my folders are now set to the Sweet Rainbow theme.
Now on to the Candy Icons.
Here is the page for the Candy Icons:
Once you download the candy-icons.tar.xz than extract the tar.xz.
Change directory to folder you downloaded the candy-icons.
cd (Name of directory)
Then type ls to list what's in the directory. Then mv the candy-icons to /usr/share/icons like so:
sudo mv candy-icons /usr/share/icons/
Type in your password and press Enter.
As soon as those candy icons are moved they should appear right away.
They showed in my launcher right away.
And that folks is a wrap. That's how you install the Sweet Folders and Candy Icons for Gnome on Debain 11.
Those instructions should work with any Gnome desktop environment.
BTW, the Sweet Folders and Candy Icons are also available for the Cinnamon desktop too.
Also putting the sweet folders in ~/.local/share/icons/ didn't work for me on Linux Mint 20.3. Instead I had to move the sweet folders to /usr/share/icons/.
Enjoy the day!