One remarkable thing about cactus flowers and those on prickly pears most commonly, is that the flowers on the same plant or from plant to plant can vary so much in the color of the flowers. Here you can see one flower and part of another. Guess what? They are blooming on the same plant. It is also not unusual to see the flowers change color during the day. Two cactus growing right next to each other, of the same variety, can have flowers that are different colors also. This color change can be remarkable from one year to the next.