灰 (huī): ash, gray; gray

The firewood in the fireplace burned all night; by morning, only a pile of gray ash remained.

He gently flicked off the cigarette ash and pressed the butt into the ashtray.

After the volcano erupted, the entire town was covered by a thick layer of volcanic ash, as if blanketed by a gray cover.

Grandma was busy at the stove, a bit of firewood ash smudged on her forehead, but she didn't bother to wipe it off.