Game Design Question #1

[freetrav]

Assume that there is a card game that requires six suits in the deck. Obviously, as long as one does not need more than thirteen unique values per suit, four of the suits can be taken from any standard deck of cards.  The other two suits, however, will need new symbols, and possibly a new color as well. Ideally, these new symbols/colors should fit in, stylistcally, with a standard deck of cards. So, the question: What should the symbols be, and what color(s)?