Yellow is fake gold; it's veneer and show rather than substance. We see that with the yellow cocktail music at Gatsby's party (1) and the two girls in twin yellow dresses who aren't as alluring as the golden Jordan (3.15).
I think a moderate income is income above the median for famlies in your county, but not more than 25% of the median income. The IRS usually has this info for free, but I see they are now charging $10 for this on their web site for more recent years. http://www.irs.gov/taxstats/indtaxst...=96947,00.html.
Updated May 23, 2017. Definition: Middle-class income is between 67 percent and 200 percent of the average median income. That's according to the Pew Research Center. There's no official U.S. government definition of middle-class income, as there is of the federal poverty level. The average median income is exactly in the middle of the range of incomes. Half of Americans make more and the other half make less.