A very appropriate choice for the challenge it is certainly very colourful. Your composition is good too, the red dinosaur is particularly dominant but not too overpowering leaving room for the blue dinosaur too. What I think lets it down is your selections for the saturation, it is obvious in the paler portions of the sky in the more intricate areas that were not included in your original selection. Overall a good and appropriate image for the challenge, well done.
Thank you very much for your valuable comments. Your point on the sky, well noted.
It was a pale morning sky. I tried to crank up the sky, but I didn't manage to get the effect. Will work on it again on my own to check on how to make it more popped.