From thumb to pinky: Sally Hansen HD Color in Spectrum 2 coats, Sinful Colors in Midnight Blue 1 coat, Hot Topic Warpaint Beauty in Galaxy 2 coats, OPI in The Flowers are Blue-Ming! 1 coat, and Zoya in Song 1 coat
So to me, Spectrum seemed to be more of a blue green and a bit sheerer than the others, as is usual with the Sally Hansen HD collection. Very glittery though! The OPI was the glitteriest out of them all, and had excellent application in just 2 strokes because of its wide brush. Galaxy was sheer but the 2nd glitteriest! Very nice sparkle. This one didn't have the red glitters that the OPI had. Then the Zoya and Sinful Colors were the darkest. The Zoya just seemed to have a tad more shimmer, and a slighter darker blue base. So what do you think? Which blue is you?