Yes, you can change the background color to fit your content, by just appending a valid HEX Color Code to your url.
As an example we take this generated url:
http://pdf2lp.net/result.php?v=4824f269ecffc274aed01cbf3d0fe99484b02a38
And add the background-color red to it:
http://pdf2lp.net/result.php?v=4824f269ecffc274aed01cbf3d0fe99484b02a38&bg=ff0000
Notice: We added "&bg=" at the end of the URL and the HEX Code Color (#ff0000) without the "#" at the start.
See Also: