1. Go to THIS site to see an example and copy the code. Go to Customize > Edit HTML and paste it between before the </head> tag. If it doesn’t work, try pasting the code before the </body> tag. Click Update Preview to see how it will look like and, if you like it, click Appearance and then Save.

2. Changing the colors (it must be HTML colors): replace the codes below with the HTML colors you want, one by one.