灰
はい · hai · JLPT N3 · noun
ash
灰 = hand 𠂇 over fire 火: fire cool enough to touch is ash
The top stroke is an old form of hand, and below it sits 火, fire. Read as a whole, it is the fire you can hold once it has burnt out. For the sound, はい is like high: ash drifts high above a fire. 灰色 (haiiro) is ash colour, which means grey.
灰 — hand 又 (ナ) + fire 火
灰 originally depicted a hand (ナ, simplified from 又) holding or reaching into fire 火, representing the cooled ashes one can safely pick up after a flame dies. From this concrete sense of 'ashes,' the meaning extended to the color gray and figuratively to discouragement, as in 灰心.