grey black
黲 describes a specific dark, muted color: a greyish black or dull dark blue-grey. It is a rare color term for a somber, faded black tone.
黲 combines 黑 (black) with 參, which likely contributes the sound and may relate to the idea of mixing or shading, suggesting a mixed or muted black color.
The left side 黑 means black, and the right side 參 looks like a complex, shadowy figure. Imagine a dark, faded black like the color of an old, dusty shadow.
For サン, picture the sun (サン) setting and turning the sky a greyish black: sun -> サン, and the color fades into 黲.