Illamasqua Mottle is a slightly warm-toned, light green with a glitter finish. It is a limited edition nail lacquer that retails for $17.00 and contains 0.5 oz.
Illamasqua Mottle Nail Varnish ($16.00 for 0.50 fl. oz.) is described as a "speckled green." It's a pale, pastel green with very subtle yellow undertones with small black glitter and larger, hexagon-shaped black glitter pieces. I couldn't even think of a dupe for the base color, let alone one with both components! I was totally stumped. A few readers have mentioned that Hard Candy has dupes for Illamasqua's speckled polishes. I haven't seen Hard Candy's in person, but from promo photos, it looks like the glitter is smaller and more circular with a combination of white and black glitters (and it seems to vary depending on the base color), but both brands are using pastel base colors with glitter to give it a speckled/sprinkled effect. Deborah Lippmann's Staccato Collection also features three pastel-hued colors with small black glitter (bottle photos suggest that Deborah Lippmann and Hard Candy's are closer to each other). I haven't seen Deborah Lippmann's in person either. You may prefer the effect or composition over the other, so pick your poison! :)