I can't be sure, but from your explanation it sounds like a dye stain was used. Dye stains don't sit on the surface like pigments do. Some thoughts:
- On a small inconspicuous spot, test putting some laundry bleach on a small spot and let it sit overnight to see if the color is gone or reduced. It sometimes takes a couple coats to get back to a neutral/original wood color
- Again, on a small inconspicuous spot, test applying a coat of a product called Sealcoat. It's diluted shellac, and will "seal" in the old stain. This can be done whether or not you try the bleach.
Step 1: Apply to the test area.
Step 2: Let dry for an hour, then test the gel stain.
Step 3: If you like the color - great. If it doesn't look like you want, then you can immediately remove the gel stain with the appropriate solvent (water for water base, paint thinner for oil base).
Step 4: If you're close, you can either let this coat dry and then attempt using a different shade of gel to get the color you like, or remove as in Step 3
Bob "Boardman" Borders