The color of your go-kart is based on your penguin's current color.
Depending on the lap number, the lights your penguin drives past change: yellow for first lap, Blue for second lap and Purple for third lap. This feature was also introduced in Penguin Games, though you had to stand next to each bulb rather than passing by it.
Elements of the old Stadium design before June 2014 were spotted.
The announcement in the magazine issue. (NOTE: The penguin is black but the go-kart is green.)