As you look at this scene, your eyes are immediately drawn to the large sea turtle swimming across the center with its beautifully patterned shell. Just below, a friendly octopus rests near the entrance of a mysterious underwater cave. Scattered across the ocean floor are jagged rocks and delicate starfish clinging to the surfaces. You will also find various types of coral and tall, flowing seaweed that provide a perfect hiding spot for the tiny fish darting through the water. Clusters of small bubbles float upward throughout the page, adding a sense of movement to this vibrant aquatic landscape.

For the sea turtle, you might try using different shades of green or brown on its shell to make the patterns stand out. The octopus looks wonderful in bright oranges, purples, or even pinks to contrast with the blue background. Since this is a cartoon style, you can use very bold and saturated colors for the coral and seaweed. Try layering light blues and teals for the water, leaving some areas lighter around the bubbles to give the appearance of sunlight filtering down from above. Using a darker shade inside the cave will help create a sense of depth and make the foreground characters pop.