Why do accessory pigments become visible in the fall?

Accessory pigments, such as carotenoids and anthocyanins, become visible in the fall due to the breakdown of chlorophyll as daylight decreases and temperatures drop. As chlorophyll degrades, the green color of leaves fades, revealing the yellow, orange, and red hues of these pigments. This change not only contributes to the vibrant colors of autumn foliage but also plays a role in protecting plants from damage by excess light and UV radiation.