Cosmos comes in various colours and at the moment I have only had the pink ones but I might try another colour this year (2016) - maybe a pink one plus a white one.
An excellent flower for attracting hoverflies of all sizes and bees - lots of the smaller bees love them.
I usually buy the plant rather than do my own seeds and keep mine in pots in full sun. Needs to be kept regularly watered and as the flowers die off, cut them off to promote new flower growth. New flowers appear all the time throughout the summer - the more you trim, the more you get.