You can try typing the name of the color in place of the hex code. For basic colors this will work with most browsers. The image will be placed over the color. This means users who do not load images will see the color of your page, but not the image. Once the background color is changed it may be necessary to also change the text color.
Light text works well on dark backgrounds and dark text works well on light backgrounds.
This will change the text color for the entire page. The default font size is 3. Valid sizes are between 1 and 7. If you use a script to handle the results put the name of the script here. If you use a script you can specify the target window.