gradient

gradient(stops);

Creates a continuous color scale. Colors are interpolated across the numeric range of the fill field.

stops type	Behavior
string	Named scheme: "viridis", "blues", "reds"
string[]	Custom color stops interpolated in LAB space

// Named scheme
chart(data, { color: gradient("viridis") })
  .flow(spread({ by: "category", dir: "x" }))
  .mark(rect({ h: "value", fill: "temperature" }))
  .render(container, { w: 500, h: 300 });

// Custom stops
chart(data, { color: gradient(["#f7fbff", "#08306b"]) });

Built-in schemes: "viridis", "blues", "reds"

See also palette for categorical data.