Why fixated on using Color Balance ? You are trying to balance Black which has no color. Really that tool is meant for photographs.
You can use that tool if you pre-fill with some other color, I used a cyan-ish here.
Better if you use some other tool, colorize is a safe choice.
You can use that tool if you pre-fill with some other color, I used a cyan-ish here.
Better if you use some other tool, colorize is a safe choice.