A shade of green named after the scouring rush (Equisetum hyemale), a reed-like plant that was very common in Japan. Kariginu (formal garments) dyed tokusa-iro were a popular choice for samurai and the elderly throughout the middle ages. It was considered an easy color to wear because of its muted, natural feel. In textiles, tokusa-iro was produced by first dyeing fabric deep blue using ai (Persicaria tinctoria), then dyeing it yellow with kariyasu (Miscanthus tinctorus).
Tokusa is also written 砥草, “polishing grass”, because its tough stalks were dried and used like sandpaper in woodworking and to polish blades. An alternate color name for tokusa-iro is かげ萌黄 (kage-moegi), “dark bud yellow”.
