Simply upload an image and start picking
The above tools is built using the HTML 5's canvas API's getImageData function. This function returns an array of pixel data for the image loaded on the given canvas. Once we have that image data, we can traverse through it to get the exact value of a pixel.
You can read all about it here on my medium post - https://levelup.gitconnected.com/how-to-extract-the-colour-of-a-pixel-using-javascript-html-5-f3661f54473
Code for this tool is part of a react component and it can be found here - https://github.com/metacollective9/canvasfun