Grim Dye

Strange Plants are the only route in, and the Dye Trader hands back a random dye from his pool each time you bring him one. You cannot ask for this specific dye, so it is luck plus volume. The plants regrow on the surface over time, which means a lap past biomes you have already cleared keeps paying out. Look for a small sprout whose colors do not match the ground it is sitting on.

It pulls the whole sprite toward a dark blood red and wraps a shadowy shimmer around the edges, close to what Loki's Dye does but warm instead of cold. It works on armor with big flat panels and buries the detail on anything busy. Since it darkens as well as tints, pair it with a light pet or a glowing accessory so you can still find yourself in a dark cave.