gradient

Mapbox line-gradient — set a color expression that's evaluated along the line's arc-length parameter. Typical use: ["interpolate", ["linear"], ["line-progress"], 0, "green", 0.5, "yellow", 1, "red"] for a route-elevation tint. The layer subdivides each polyline into MvtStyleRule.PaintSpec.GRADIENT_SUBDIVISIONS piecewise-constant segments for rendering.