ColourPop Wavelength is a cool duochrome with a sparkle finish that is limited edition and retails for $9.00. In comparison, Pat McGrath Astral Lilac Aura is a cool lavender with a sparkle finish that is permanent in palette and retails for $25.00.
Pat McGrath Astral Lilac Aura is 85% similar — it is more shimmery, warmer.