There exists ready-made Chrome extensions for some colors like Blue, Green, Pink and for all other colors you can tweak the script file in code package. Details are available on the developer page here. All you have to do is download the code [link] and then change the color code in contentscript.js file. And then to install the newly cooked extension on Chrome you have to open Extensions, click on “Load unpacked extension” and load the unzipped folder. Good to go.