Based on temptalia and others' swatches, I reckon I got a dud bottle of Force (however, a dud bottle of Illamasqua is still decent by other brands' standards). Whenever I put top coat on mine, it darkens the colour in patches and leaves drag marks. I know, I know, it sounds like "you're just putting top coat on too early, fool" but one time I tested this by putting top coat on several hours after painting my nails and I still had this issue. Oh well. I might repurchase if I see it on sale, coz even with this issue, it's still very long-wearing and pigmented.