how to play Pixies - Flower Power

About Pixies: Flower Power, from BoardGameGeek:

Pixies Flower Power booster of 14 new cards, still designed by Johannes Goupy and illustrated by the artist Sylvain Trabut, will now allow you to play from 2 to 6 players. It adds 2 simple rules that will really change your approach to the game and scoring: Two-colour cards have been introduced to ‘simplify' your life (but with a malus on other colours) At the end of the round, each face-down card scores 5 points (minimum). -description from the publisher