This interesting code snippet was created by Urban Sandén on Codepen, and it is just two simple check buttons. Nothing happens by default, but the cool part comes when you select one of them, changing the whole background and matching the essence of the button. So if you choose the “Greyscale” button, it will show an image with that color composition, and if you select the “colour” one, it will switch the background image to a full colored one with a nice transitional effect.