Hello, I have a problem: my video consists of a talking person who stands almost still, and the background is a white/gray/yellow wall. I would like to get rid of the wall and replace it with blue background. How to do it?

I tried using chroma key in Premiere, but it doesn't work because everything turns blue. I am not sure if that's because I used it somehow wrong or maybe it's not possible with background that is white/gray/yellow (there is always green or blue original background mentioned with chroma key tutorials).

I also tried Difference Matte, but it produces strange results. I haven't any still image with only the background, so I exported a frame and simply covered the person with white, leaving the wall in its original color. But that might not work. The exported+imported frame size also chaged, duno why.

Anyway, what would be the right approach for this task in this particular case?