WebGL gets ride of background?

When I publish my project the background works fine on a PC build. When exported through WebGL… it gets rid of the background and is just blue? Here is a link to the images: Screenshot - d59b688e2fdcf92072f5531d4626d4d7 - Gyazo

How is your background generated?
Is it supported by webGL?
Is there some override setting that is turning off your background?