Because the inventor was a painter, seitai (a blue pigment used for Japanese painting) and hikari-beni, also referred to as tsuya-beni (a red pigment made from safflowers), used for Japanese painting were used to color the patterns.
考案者が絵師であったこともあって、当時は日本画の顔料として使われる青黛や艶紅などを柄の彩色に使用した。