In a computer, the so-called “how much” of RGB refers to brightness and is represented by an integer. Typically, RGB has 256 levels of brightness, expressed as numbers from 0, 1, 2… up to 255. Note that although the number is up to 255, 0 is also one of the values, so a total of 256 levels
Since web pages (WEB) are media developed based on computer browsers, colors are mainly optical colors RGB (red, green, blue).
Using this RGB color calculation tool, you can add any two colors and get a new color to help you calculate the appropriate RGB color during web development.