Spirit is standing in a field of snow on his first winter, with trees in the background and the sun shining brightly down on him. His coat is a silvery grey, contrasting with the pure white snow covering the ground. To capture the brightness of the sun, I would use bold, bright yellows and oranges for Spirit's coat, and a lighter shade of yellow for the snow. Dark browns and grays can be used for the trees and grass, while the sky can be painted with pale blue and icy purples. Finish the scene with glittery white dots around Spirit to represent glittering snowflakes.