There are a 3 limited options you can use to change that
The first place to try is File menu > Options command > General option > Personalize your Copy of MS Office section
In the "Office theme" drop down try the other color options.
The other place is try different Windows themes. Some of them may affect that part of the user interface.
http://www.bbc.co.uk/accessibility/guides/chang...
Try finding and downloading themes from the internet.
Finally, you can try changing the Ease of Access options
http://www.bbc.co.uk/accessibility/guides/ease_...
Try the High Contrast options
http://www.microcenter.com/tech_center/article/...
**************** "Disclaimer" **************
We are forced to include this Standard boilerplate legalistic bafflegab disclaimer for any links to non-Microsoft websites:
(Short form: use these links at your own risk, just like everything else from MS!)
The link(s) to non MS-page(s) appears to be providing accurate, safe information. I suggest you stick with the “manual” instructions. Unless I explicitly suggest it, avoid downloading their “utilities”. Thoroughly research any product advertised on the site before you decide to download and install it. Sometimes they include 3rd party programs, "unwanted" programs that are automatically installed during a standard install. So, if offered, do a "custom" install and carefully read each step. One of the steps MAY give you an option to install, or NOT, "additional" programs. 99.9% of the time you don't want to let them be installed. For example, when you install Adobe Player you are given the option of installing 2 additional "free trial" programs: Potentially Unwanted Programs: MacAfee Security Scan and MacAfee Safe Connect. The option to install is turned on, you have to manually turn it off. Those are PUP's. If you click "OK"/"Next" without paying attention you get the 2 "extra" programs.
As well, watch out for ads on the site. They may advertise products that include PUPs. Thoroughly research any product advertised on the site before you decide to download and install it.
************* End BS Disclaimer ************