| Answer | Crossword Clue |
|---|---|
| INDIGO | Dark dye |
| ANIL | Dark-blue dye |
| COALTAR | Dark dye ingredient |
| methylthionine | as in methylthionine chloride, a dark green dye used as a stain, antiseptic etc |
| indigotin | A dark blue crystalline compound that is the main constituent of the dye indigo |
| methylthionines | METHYLTHIONINE, as in methylthionine chloride, a dark green dye used as a stain, antiseptic etc |
