I too feel that a dull Japanese Maple still has great color when compared to other trees. But I think we can all agree that some years, the colors are much better than others. I thought the article covers the science well, but it is general; i.e. not specific to any one variety of tree. But much of the science still applies to our Japanese maples. It does provides a good understanding of the science behind the colors and what is needed for optimal peak colors. So I felt it was worth posting, because some may have not seen it before. I agree that the timing of visible color and peak color is different every year, maybe they are referring to the nights reaching the threshold value, starting the process, happens at the same time each year. But environmental factors can speed up or slow down the color display, as mentioned later in the article.