We recently reviewed a Chrome extension that allowed you to set a background image for your Google+ profile. If a background image wasn’t quiet what you had in mind and would be satisfied with just changing the background color or perhaps tweaking a few things in either the left and right column as well as the Google bar then try Google+ CSS. It’s Chrome extension that adds CSS tweaks to your Google+ profile. It allows you to float columns, bars, set background, text and link colors for different columns and hide profile suggestions among other features.
Be warned that the extension might conflict with some of your already installed ones and might not work unless you disable them (case in point Web Shotty). Once installed, go to the extensions options and start customizing. The options are divided in to different sections; Floating, (To make bars or columns float); Top Bar. to hide links in the Google Bar; Left Column, to hide profile picture, name, the welcome link, Stream, Incoming stream link, Sparks, Chat and change the background color of the left column, header colors and text colors; Right Column, Hide features like, In your circle, profile suggestions, Hangouts and more and set background, header and text color; Design, lets you change the background color of the page and make color changes to elements in the center column.
Once you’ve set your preferences, hit Save And Refresh and the extension will refresh your Google Plus page to reflect the changes.
Install Google+ CSS Extension For Chrome
Update: This extension is no longer available in the Google Web Store. There are no similar alternatives that we know of, however you can try GTools+ extension.