Here is a precis of the stories that echo in the Ransom's Egg "color scheme".
Red: Raven bought light to the world. He retrieved the sun from the "box of daylight" where it had been hidden away.
Red is also for the salmon, "keystone" species (the species that ties the ecosystem together). Raven and Fog Woman, Queen of the Salmon People were paramours. Raven's foolishness spoiled their love.
Blue: Raven retrieved the world's water by pecking holes in a great Toad that swallowed it all. (Sara Mall has turned this story inside out and recast it from a less heroic, more feminine perspective wherein the mother toad saves the water so it may be dispersed incrementally and everyone gets their share.) The water flowing from the eyed salmon eggs is a poetic echo of the original story.
Green: Raven is the comic lord of the forest, the trickster that rules by not ruling. Salmon is his secret queen, hence the eyed eggs on mother raven's cloak.
Cedar: The cloak of Raven's mother is cedar, the everlasting mother-wood of the Pacific Northwest. It made blankets, baskets, canoes, houses, totems, utensils, rope and was key to kindling fire.
The heroic raven is curled up in the egg his mother is turning as the world whirls around her. Defiant, fierce, and yes, and ironic in a kindly tragi-comic way, she knows, as all mothers do, that the mother is fate. Her care compasses the heart of the "hero".