It generally will lighten somewhat. Usually not extreme. Most of the excess dye is in the jigging, where it's usually very dark to start, and most of what comes off will be from there. If you do try wiping with some solvent, I'd do it very lightly. Just lightly moisten a rag with some WD-40, and give the scales a light wipe-down. Look at the rag to see how much is coming off, and that'll give you some idea of how much more you want to do. I'd do this just a little at a time, and give the knife a few days between these wipedowns. Any residual excess dye will have more time to stabilize, that way. I sort of prefer the WD-40 for this, because other solvents, like alcohol, will be more aggressive at removing the color, and will also strip moisture away. WD-40 is a bit gentler, and will also leave a little bit of mineral oil behind, after the solvent evaporates. I've found that leaves bone scales looking pretty good, with a little gloss to them. If it feels just a bit oily, wipe it down with a dry, clean rag.
Edit:
As I mentioned earlier, this is usually more effective on new knives, freshly unwrapped from the factory. Knives that've been allowed to air out for a while, won't give up as much of the color later. Maybe still some, just not as much.