Dark theme for PDF viewer

[ngg]

Could this be what you are referring to?

PDF background color

Hi. I don’t know about the technical difficulties associated with my request, but I would really like to have the option to change the background color of PDF documents in the viewer, like you can in Adobe reader. When reading articles with black text on a white background during evenings/nights for example, the eyes become strained so I usually changed the background to light grey when I used Adobe reader. Is this possible for you guys to implement?