The Low Country is known for its Live Oaks dripping with Spanish Moss. They are huge, and beautiful, and a challenge to paint! In my workshops, we have long conversations about what color that moss is. Why? Because it is ever changing as the light hits from different directions. Sometimes it looks grey or grey-green, and almost blends in with the color and value with the foliage. Other times, like this one, it becomes a yellowy gold because the light is coming through it. Discovery requires observation in real time.
"It just depends" doesn't seem like a good answer, but sometimes that is the ONLY answer! :)