ColourPop Zipper is a moderately warm-toned, dark purple with a matte finish. It is a permanent lipstick that retails for $6.50 and contains 0.11 oz.
ColourPop Zipper Ultra Matte Liquid Lipstick ($6.00 for 0.11 fl. oz.) is described as a "deep blackened purple." It's a dark, eggplant purple with slightly warmer, pink tones and a matte finish. This shade was difficult to apply, as it wasn't opaque and looked uneven on the lips. When I tried to smooth out the color more, it was already drying down, so some places were thicker than others (notably, on the middle of my lower lip, it looked bumpy). The finish is mostly transfer-resistant. The color lasted for seven hours on me with a stronger fade through the center of the lips than with some of the other shades. It was somewhat drying after five hours of wear. ColourPop Lychee (P, $6.00) is lighter, brighter. Anastasia Vintage (P, $20.00) is lighter. MAC Heroine (P, $16.00) is lighter, glossier. Maybelline Vibrant Violet (P, $7.99) is darker, less glossy. See comparison swatches / compare dupes side-by-side.
FURTHER READING: Formula Overview, which is a detailed review of the range as a whole.