If the style or customization options don't work, install the Stylus extension (not Stylish ⚠️).
After installing Stylus, install the style from here instead and click Install
You can now customize your style. After you’re done, click Install style to the left (For help setting a custom background, see step 4 under How do I set my own background?)
If you ever want to customize your style again in the future just find Stylus under your extensions and click the ⚙️ icon net to the style name
(Only applies to users who downloaded from userstyles.org)
⚠️ If the style is already installed, uninstall it ⚠️
Click the ⚙️ icon next to Install Style (button may look different)
Scroll down until you find the Customize options
Choose your options, then scroll back up and click Install Style
If it doesn’t work, that means the website is broken.
Follow the steps in Why doesn’t the style work? to have the option to change the background brightness. You’ll have to install a different extension due a glitch with Stylish.
Go to the Discord website and press F12. You will see a new window that looks like this (don’t worry this will be easy)
Scroll to the bottom of the top window. You will see a line that says “stylus” in it
Click the ▶ Arrow to the left of the line. Double click to select all this new code and copy it