You can use getCSObject to change any attribute or value found in the raw HTML of a rendered page or as seen from DOM explorer in IE.
As seen in the screenshot the "colour" can be set to red as seen in the "Styles" tab. getCSObject([Control Name]).style.color
Also the Text of the button can be changed using the "value" of the object as seen in the DOM explorer currently set to "Bob". getCSObject([Control Name]).value
When examining the HTML structure you will sometimes have to navigate to the child or parent to find the attribute you want related to the objects name.