This extension is related to color change of any page or background where you want . If you reading any blog or article and you want to change the color of background of any color that you like or your eyes feels easy to read with that color you can change. https://www.bestchromebookpro.com/
If you want to change color to red then just choose red and color of background will be red or if you like to keep blue background then pick blue color even you can change any color of background you want to change.
