Dawn is the opposite of Twilight. Her color scheme is much brighter, and in shades of pink instead of purple. She has a strong magic ability like Twilight, but doesn't know how to unleash its full potential. Unlike the other opposites, she has no cutie mark.
Greyscale Trot is the opposite of Rainbow Dash. She has a color scheme of various shades of grey. She is more accepting of her friend's abilities, and doesn't boast much. Her cutie mark is a rainbow connecting two clouds, but greyscale.
Crabby Cake is the opposite of Pinkie Pie. She has a green color scheme. She is anti-social and easily tricked off. Her cutie mark is a cake with crab claws.
Lemon Zinger is the opposite of Applejack. She has the same color scheme as Applejack, but switched around. She isn't very honest and tries to avoid trouble by lying. Her cutie mark is a juicer.
Boltzoom is the opposite of Fluttershy. She has a pale blue color scheme. She is much more outgoing than her counterpart. Her cutie mark is three butterflies, but with fancier wings than Fluttershy's.
Pauper is the opposite of Rarity. The only difference in appearance is that her mane is messy. She is poor and uses scraps she finds to make clothes. Her cutiemark is two rags being sewn together.