Prior to 1992, most election maps referenced Republican in blue and Democrat in red. However, after 1992, the media determined that using red for Democrats might be editorially construed to suggest that Democrat politicians and policies were in line with those of Socialist Democrats, which, of course, they are. Notably, with a couple of avowed Socialists in the 2016 election, maybe the media will revert to the old colors.
Below are examples of the previous party colors on earlier maps and a map we recreated in those colors showing the stark contrast between urban Democrat strongholds and grassroots Republicans.
Reagan Presidential Library 1984 Electoral Map
George HW Bush Presidential Library 1980 and 1984 Electoral Maps
Urban v. Rural Electorate