Tokens are special items in Crash Team Racing and Crash Nitro Kart where you need them to be able to race on Gem Cups. In CTR, tokens come in five colors: red, blue, yellow, green, and purple. In CNK, they come in only four colors: red, blue, green, and purple.
Ways to get them
Depending on the color of a Token, there are different ways to get one. In CTR, you need to get the letters C, T, and R in a race, and come in first place on the race. This applies for red, blue, yellow, and green Tokens. In CNK, this is the same, except you need to get the letters C, N, and K instead. This applies for red, blue, and green Tokens. However, there is a different way that purple Tokens are obtained. After defeating the boss of a planet/area, a new level will be unlocked where you need to collect all of the Crystals in the level before time runs out. Doing so gets you a purple Token.