I am not able to alter my header colors from the standard Kubrick colors (blue).
Default theme. No additional stuff added to the header. The font color will change. The header top/bottom colors will be retained when I Update Header. (The color does not change on that page; only the hex's are saved.) Visiting the site confirms that only the font color has been changed.
I have tested this using both the color pickers and the advanced mode using a variety of standard and non-standard colors. Every time the hex is saved and no color change (from the default blue) appears--any OS, any browser.
Also, the page is called Header Image and Color but I see no means for altering the image.