Colorful Windows is a personalization extension for Firefox that enhances the browsing experience by introducing a variety of vibrant themes. Each new window opens with a randomly selected theme, creating a visually stimulating environment reminiscent of peacock colors. This feature allows users to enjoy a unique aesthetic every time they browse, adding a layer of creativity to the standard web experience.

The extension operates on a subscription-based model, providing users with continuous access to its dynamic theme library. It's important to note that in some cases, a reload of the Firefox browser may be required for the new color themes to take full effect. Overall, Colorful Windows offers a fresh and colorful way to customize the Firefox interface.