The description of the origin of color from a physics and physiology perspective is helpful and accurate. I would urge caution about drawing firm conclusions from that. That does not mean that no plants evolved to reflect wavelengths that appear to animals as vivid colors. It seems to be the case for trees that the colors are a side effect of what they are really doing, but that is not a conclusion that applies to all plant colors and cannot be proven by the physics and physiology of color.