Pixolor is a tool to find out exactly what color each of the pixels that make up an image on your Android screen is. Regardless of whether you're viewing a picture, Twitter, or WhatsApp, all you have to do is slide the Pixolor circle over the bit you want to 'capture' and it tells you its exact color straightaway.
The app displays the RGB color code within the circle as well as the DIP coordinates for any pixel onscreen. Thanks to these features you can quickly find out, for instance, which Material Design color is closest to the one you have inside the circle. You can obviously also pinch the screen to make the image bigger and your task easier.
Pixolor is a very useful tool for graphic designers, as with it you can identify any color used within any app.