Pansies (violets) are among the few flowers that seem truly black. and I have noticed that I prefer flowers that are ALMOST black, but not quite. This midnight blue is better than black. and with that little "aurora borealis" eye in the middle.
Sow your sweet peas seeds anytime from October until March, two seeds to a pot. You can sow your sweet pea seeds in March but growing sweet peas over winter will produce stronger, more robust plants. Use toilet rolls!