Change the background color and font of web part headers
.ms-webpart-titleText.ms-webpart-titleText,
.ms-webpart-titleText > a {
background-color: black;
/* changes the background color of the web part header. Hex too! #000000 */
font-size: 20px;
/* Font Size */
font-weight: bold;
/* Font bold, italics, */
color: white;
/*Font color */
padding: 5px 5px;
/*padding around fonts */
}