I like the otter color, and if you're looking at Tarrago self-shine dyes, you can definitely cover the previous color. The brand says you can dye white over black. *However," here are my concerns with these:
- From the pic, it seems like the boots might be treated with some kind of glaze that makes them nice and smooth/shiny. The dye adheres and covers best when the leather is matte and untreated. I last tried red over a shiny black, and I had to use a lot more coats to get a decent look. It still is not a perfect, solid color. I believe I've read about people stripping off glaze & previous dyes with acetone, but I have NOT tried this yet.
- The tooling isn't a pain in terms of the dye job, but since you're dying over the tooling, the designs will no longer contrast with the base color of the boot the way they do now.
- Would you end up wearing these tooled leather boots with your mod dress and sweater dress even if they are gray? Even if the color changes, IMO tooled leather is a pretty Western statement that may not go with the style other gray items you have (not 100% sure on this, but it's something to ponder).