Web Development Requires a lot of Customization and proper Html. And now This HTML is useful in every field whether we are talking about colour customization,site layout, adding a functionality etc..
Having different background and border colors adds a spice and a new identity to any specific element in your blog page but Sometimes its very difficult to find a appropriate color and the hex code of that color.
So you can use Colorzilla plugin to get the Hex code of the color displayed on your screen.
With ColorZilla you can get a color reading from any point in your browser, quickly adjust this color and paste it into another program. You can Zoom the page you are viewing and measure distances between any two points on the page. The built-in palette browser allows choosing colors from pre-defined color sets and saving the most used colors in custom palettes.
But if you want a complete list of Hex Colour Codes.