I have a strange problem. Some of my DVD -> MKV conversions comes out with grey subs when muxed in the MKV file. I then removed the subs from the MKV and loaded the IDX/SUB externally and the subs were fine, white with black borders.
I then thought it was fine and remuxed the IDX/SUB into the MKV file but then, they were back to grey with white border.
What might be wrong?
TIA