Motion edit prompt

Keep the rainbow completely stationary with no position, scale, rotation, or shape changes. Animate only the fills of the three rainbow bands in a smooth looping hue cycle. Begin with the outer band orange, the middle band yellow, and the inner band green. Then shift the palette so each hue appears to travel outward from the inner band to the middle band and then to the outer band: the bands pass through green, cyan, blue, purple, red, and back to orange. Maintain the same slight darker overlay/shadowing and opacity relationships so the lower overlaps and rim stay subtly darker while the colors change underneath. End the loop by returning to the orange-yellow-green arrangement in the provided SVG.