Change background color for cropped panoramas?

[Diego-Tab]

Hello, please. The issue title is self explanatory. My pages have either black or white background. Photo Sphere Viewer cropped panoramas with their black background look good on black pages but I'd like to change the background color of the viewer to match the one on white pages. I tried my best editing the photo-sphere-viewer.min.css file, the 'viewer' div tag and the configuration script but with no luck. Thank you!