The box used in the lottery is mentioned almost thirty times in the story more than ten times in the phrase the black box. Why does the author emphasize this object and its color so strongly?

The box used to be a cornerstone of the ceremony. The strong colour and ornamental trappings were a big part of the tradition. The box has, over the years, faded in colour and is falling apart. The people do not care about its tradition, they only care about stoning the "winner" to death. The real reasons for the lottery, whatever they were, have been forgotten.