As an entrepreneur of some principle, McCoy had no known ties to the organized crime syndicates that flourished during Prohibition. He was cheating and they caught him red handed. We tried to follow up on that lead but it was a red herring. People who opposed fox hunting would drag a red herring across the path of the dogs, they would follow the scent of the herring and loose the trail of the fox. Just a red herring to get the minds of the voters off the sins of the 80th Congress.
Today is a red letter day, so that's the reason for it.
And in the morning it will be foul weather today for the sky is red and lowering. The real meaning is that bent over working in the fields, even with a broad-brimmed straw hat which only provides intermittent protection, after a number of years the neck is likely to get a dark brownish red permanently. The sun in the south being more intense than in other areas of the country. The landlord couldn't afford to toss away food, so cooks often made hash from leftovers. Guests usually complained but if they pushed hash aside, they were likely to get it the following day in the form of meat loaf.