Hello. For a published course with a simple background, the tag background controls the color. You can add the following code to a button or item to change the CSS for the page's background color. You could create a button or other object with an action on it. For example, a button with a "On Mouse Click" trigger, and an action to "Run Javascript". Then place this code in the javascript box:
triv$( 'body', getDisplayDocument() ).css("background-color","red");
You can change the "red" to any valid CSS color, or use rgb() function in double quotes:
triv$( 'body', getDisplayDocument() ).css("background-color","rgb(0,0,255)");.
You could also change a background image with code like this on the "background-image" property.
