Small application that gets color information from screen

I need an application that is supposed to get the dominant color from one screen that is connected to the computer, and provide it in hex or rgb values. It should be dynamic, meaning it doesn't get the color from a single image, but from the actual output, and gets refreshed every n seconds. For example, when I watch a movie or play a videogame, the app output should contain the hex/rgb code of the color that is dominant on screen, continously. Think "ambient light" but instead of LED strips, colors are written down as hex/rgb values. I prefer Visual Basic or Java, but you are free to do this in any programming language you choose. You are required to provide the source code, any additional files and resources, and a compiled exe for testing purposes. Additional details will be discussed after the job is awarded to you.