Orizon (Background / Footer)

I purchased this theme back in 2016, and tried to set it up for a project which I forgot, and remembered I had the same issue I have now. The blue theme preview on themeforest, and on your website is incorrect. ?

I have been unable to get the blue background as shown in the preview when i first bought it and now, not sure if its a fault on your side forgetting to add it, or Its my end, I dowloaded all the files, and on the themeforest page it says I can choose between multiple backgrounds, but I am unable to change, or upload anything other than the a turqoise blue background, and then the red themes background.