Being able to add colors to your labels in Gmail is nice, but having icons is even better. See how to liven up your Gmail inbox with this user script.
To use the script in Firefox you will need to have the Greasemonkey extension installed. Once the script is installed simply refresh Gmail if you had it open in a new tab. Click on the color selection arrow and your new icons will appear above the colors as shown here. Choose your new icons the same way that you would for colors.
New to Greasemonkey? See our article on using Greasemonkey here.
Note: During our tests we were unable to get the script to work in Google Chrome or Chromium browser.
Gmail Labels Icons [Userscripts.org]