One of the biggest trends in interactive mapping in 2016 is mapped visualizations of sports data. If you are thinking about creating your own sports data map then you might also want to think about styling your map tiles to match the colors of your favorite sports team. Luckily Teams Basemaps has done all the work for you.
Team Basemaps provides team base maps in the colors of all the teams in the English Premier League, Major League Baseball, Major League Soccer, National Basketball Association, National Football League and National Hockey League. Just select your favorite team and you can download an Esri base map which matches your team's colors.
Unfortunately Team Base Maps does seem to occasionally use the wrong colors for some of the featured teams. I don't know about the US sports teams but the English Premier League base maps do seem to have quite a few errors. Just in London the red & white of Arsenal, the claret & blue of West Ham, the blue & white of Chelsea and the white & blue of Tottenham all seem to have been replaced with some random colors. Although it looks like Team Base maps has got the colors of Crystal Palace correct.
To be fair to Team Basemaps the team colors are taken from teamcolors.github.io. So the color errors aren't strictly the fault of Team Basemaps.