This styling Command alters the background colour or background image
of the attached hook. Supplying a colour, or a string contanining a CSS
hexadecimal colour (such as
#A6A612) will set the background to a flat colour.
Other strings will be interpreted as an image URL, and the background will be
set to it.
(background: red + white)[Pink background]
(background: "#663399")[Purple background]
(background: "marble.png")[Marble texture background]
Combining two (background:) commands will do nothing if they both influence the
colour or the image. For instance
(background:red) + (background:white) will simply
produce the equivalent
(background:red) + (background:"mottled.png")
will work as intended if the background image contains transparency, allowing the background
colour to appear through it.
Currently, supplying other CSS colour names (such as
burlywood) is not
permitted - they will be interpreted as image URLs regardless.
No error will be reported if the image at the given URL cannot be accessed.