Right
彡 supplies the sound — exact match shān with no drift.
彡 itself depicts three short slanting strokes representing fine hair, ornament, or decorative pattern. That 'pattern, ornament' image lends a faint semantic flavour: a shirt, often the most decorated layer of clothing. Same series:
衫,
杉 (fir tree),
衫 contributes to the patterned-shirt picture.