The colour yellow is traditionally related to the condition of cowardice, and we can see from the title that yellow is very important from the way that Crane has chosen to call the home that the bride and the marshal are heading to. However, the symbolism of yellow and how it relates to cowardice is shown to be linked to the main theme of power shifts. At the end of the story, the marshal and Scratchy have a contest of power, and this is interestingly won by the marshal because he deliberately refuses to engage in Scratchy's "game" of power. Note how Scratchy responds to this apparent surrender:
He was not a student of chivalry; it was merely that in the presence of this foreign condition he was a simple child of the earlier plains. He picked up his starboard revolver, and, placing both weapons in their holsters, he went away. His feet made funnel-shaped tracks in the heavy sand.
Scratchy's retreat thus reveals his own moral cowardice and bluster. Power relationships are shown to be suddenly reversed, and the symbolism of yellow can thus be seen to refer to this power relationship and how it suddenly changes.
Having a number of symbolic meanings, the color yellow in Crane's story, "The Bride Comes to Yellow Sky" signifies the figurative trial by fire of the rather cowardly marshal, as well as the approach of a new era with the rising of the yellow sun against an aging tradition.
This metaphoric new day is the arrival of many from the East into the West, particularly women. In the exposition of the story, Texas marshal, Jack Potter, rides on the train as he returns with his new bride from the East, anxious about being confronted by the townspeople because he has not followed the tradition of the town in which he should have gained approval first before marrying a woman. As they approach in the train toward Yellow Sky,
[T]he traitor to the feeling of Yellow Sky narrowly watches the speeding landscape.
Hurrying his new wife along after they step down from the train, Potter hopes to avoid confrontation with any of the townspeople. Because he ignores the gesticulations of the station-agent, the marshal is unaware of the approaching confrontation with Scratchy Wilson, who represents the old untamed West. Now, with his boots that have "red tops with gilded [golden, yellow] imprints, of the kind beloved in winter by little sledding boys on the hillsides of New England."
Scratchy's defeat is symbolized on these boots. In his assault upon the marshal, Scratchy, the "simple child of the earlier plains," finds himself confronted by Marshal Potter, who has suddenly put away his yellow cowardice in sneaking off and obtaining a bride as he now courageously faces Scratchy, who aims a gun at him. Also, Wilson is confronted by Potter's bride, whose face turns "as yellow as old cloth" as she becomes "a slave to hideous rites, gazing at the apparitional snake."
Thus, Scratchy becomes representative of uncivilized ways that threaten the peace and tranquility of domestic life.
When the old East confronts the rough and tumble, shooting West, the new Mrs. Potter triumphs over this Western custom. For, having learned that Potter has brought home civilization and Eastern ways with a decent woman as his wife, it is a defeated Scratchy Wilson who says, "I s'pose it's all off now." This "simple child of the earlier plains" shuffles away in defeat, as he has become outdated in a soon-to-be civilized Yellow Sky.