ColourPop Seesaw is a moderately warm-toned, medium-dark lavender with a matte finish. It is a limited edition lipstick that retails for $6.50 and contains 0.11 oz.
ColourPop Seesaw Ultra Matte Liquid Lipstick ($6.00 for 0.11 fl. oz.) is described as a "pastel lavender pink." It's a brightened, pinky lavender with subtle, cool undertones and a matte finish. This one had good pigmentation but dried down quickly and cracked as soon as it finished drying, so it flaked a lot during wear. It felt awkward to wear (you could just feel something was on your lips) and lasted four hours before it had flaked too much to keep wearing. It was drying while worn. MAC Raspberry Swirl (LE, $21.00) is lighter, glossier (90% similar). MAC Steady Going (P, $21.00) is warmer (90% similar). ColourPop Boa (P, $6.00) is cooler (85% similar). KVD Beauty Armageddon (P, $20.00) is lighter, brighter, cooler (85% similar). MAC Pink Nouveau (P, $21.00) is darker, glossier (90% similar). KVD Beauty Requiem (P, $20.00) is lighter, more muted (85% similar). Obsessive Compulsive Cosmetics Mannequin (DC, $18.00) is lighter, brighter, cooler (80% similar). NYX Rose (P, $6.00) is lighter, brighter, glossier (80% similar). ColourPop Brills (LE, $7.00) is darker, cooler, glossier (80% similar). Makeup Geek Arabesque (LE, $12.00) is darker, cooler (80% similar). See comparison swatches / view dupes side-by-side.
FURTHER READING: Formula Overview, which is a detailed review of the range as a whole.