Yes, it matters depending on your strategy and what you are playing. Black/Red, Odd/Even, and Low/High give you the best chances of a win, but the lowest payout, so it works for a long term play. Other people like combining bets: if you bet on the top row of numbers and make a secondary bet on red, your chances of winning both are higher, but if you lose on the row you still have a chance of winning on red as insurance.