Border Colors Rogue Extension Draft
Border Colors is a rogue browser extension that functions as adware.
Like most similar rogue extensions that have hidden unwanted functionality inside them, Border Colors is not listed on the Chrome Web Store. This should already be a big red flag regarding its nature.
The extension's advertised purpose is not even too clear, and the name implies the ability to change border color elements inside your browser and the pages you visit. The additional functionality you don't want, however, is displaying ads inside your browser.
Adware does that to generate money for its maker, while you're being shown intrusive and potentially harmful ads. Adware often works in conjunction with rogue ad networks and serves up ads that may link to questionable content, scam or phishing pages and other untrustworthy websites.
You never want to keep adware of any kind on your system and you would do well to remove Border Colors immediately if you see it among your browser's installed extensions.