Need help (The Blue Hotel)

"For a time the encounter in the darkness was such a perplexity of flying arms that it presented no more detail than would a swiftly-revolving wheel. Occasionally a face, as if illumined by a flash of light, would shine out, ghastly and marked with pink spots. A moment later, the men might have been known as shadows, if it were not for the involuntary utterance of oaths that came from them in whispers.

Suddenly a holocaust of warlike desire caught the cowboy, and he bolted forward with the speed of a broncho. "Go it, Johnnie; go it! Kill him! Kill him!"

Scully confronted him. "Kape back," he said; and by his glance the cowboy could tell that this man was Johnnie's father.

To the Easterner there was a monotony of unchangeable fighting that was an abomination. This confused mingling was eternal to his sense, which was concentrated in a longing for the end, the priceless end. Once the fighters lurched near him, and as he scrambled hastily backward, he heard them breathe like men on the rack." (The Blue Hotel by Stephen Crane) http://www.4literature.net/Stephen_Crane/Blue_Hotel/6.html

Please help me to get what the author means by the blue and by the two red sentences.

Thank you so much.

Cadzao