I would approach this Halloween-themed coloring page by using a variety of bright colors and incorporating different shades of orange, purple, and black for maximum effect. I would color the pumpkin and the cat a bright, vibrant orange, and the witch's hat an almost velvety black. The cat's eyes would be a bright green, and the bow would be a mix of purples and lavenders. This intense blended palette emphasizes the spooky atmosphere of Halloween and creates a dynamic image that stands out.