There is an unclarity about how many cards you are allowed to get in each color. The rules says: "You may not have more than 6 cards of the same type on your Personal Board." but blue and purple cards are not ON your board. does that mean there is no limit for those?
There is a line in the rules that states the area to the right of the board is considered part of your Personal Board, thus the 6 card limit also works for the blue and purple cards. It is actually the bullet on page 7 right above the bullet that states the 6 card limit.