Imo if I was painting this I'd go for a sunny day theme, it could leave a huge shadow which would have cooler hues, and the sun hitting the creature and trees would leave beautiful sub surface scattered greens and oranges. You could make the rocks slightly cool grey in tone too, and because the creature is so big there would certainly be some blue (just a tad) in the atmospheric perspective.
Here's an example,
https://www.artstation.com/artwork/rRXO4J
It's a mostly green image but there are stunning deep blues in the shadows and lush bright greens and yellows where the sun hits the plants. Like this too, you could even have some cloud passing over the legs in yours to show a bit more depth!