It's so sparkly I could only bear a couple fingers of this brilliant glitter topper- it has dozens of different colored glitters with every single one holographic! It deserved a gorgeous base- so I used China Glaze Galactic Gray from the newest holo line ChG put out. As others have pointed out, it's not really gray, more of a dusty brownish-pewter with a reserved but very linear holo effect. The ChG is a very durable holo, unlike many others, probably due to the pigment/additives needed for the rainbows. HK Girl over, with a layer of Gelous on the glitter first.