premultiplied‑rgba is a tiny Node.js utility that converts a color expressed as an `[R, G, B, A]` array into its premultiplied‑alpha form by multiplying each RGB component by the alpha value (optionally writing the result into an existing array). It’s useful for graphics or image‑processing code that needs to work with premultiplied RGBA data, such as WebGL shaders or canvas rendering pipelines.