You can customize the maillot of your avatar from the simulator. Once inside the simulator, click on your photo and Avatar option will appear, if you click on this option you will see the wardrobe with the maillots you already have.
On the wardrobe screen you can see the accumulated balance (points) on the top right and a little lower the option to go to the store.
To earn points you just need to use a smart trainer or a power meter, complete the full indoor session and never use slope reduction (when in routes).
Once in the store, you can redeem your points and choose from the options that exist, the maillot that you would like to buy.
The color of the helmet cannot be chosen, it changes according to your sport level:
-Amateur -> yellow
-Active -> red
-Pro -> green
-Elite -> blue.