I looked at existing teams in Formula e and I collected a few images and extracted the main colours from the cars.
Brands like Ferrari, use the colours Red, green and yellow to represent Italy as the founder of the company (Enzo Ferrari) based the headquarters in Maranello, Italy.
This helped me get ideas for my teams colour schemes and helped me decided whether I should use certain colour combinations or just to experiment till I found colours that worked well together.
I looked on the website: https://color.adobe.com/create/color-wheel/ to experiment with colours for possible combinations for my three race teams. I ended up with a mixture of reds for the first team, blues + purples for the second team and purples and yellows for the third.