You've probably seen lots of pictures of OPI DS Glamour. There's not much to say about it, except that it is a gorgeous blue that leans to purple in some lighting. It is thought that topcoat dulls holographic nail polishes, but in my experience that has not the case for most holographics. I have noticed that with Laylas and China Glaze OMG collection it does change the effect a little bit. I have also noticed that Barielle Manicure Extender looks better with the linear holographics, such as the ones from the Designer Series Collection (like this one, Glamour). The problem is that sometimes I need a fast drying topcoat, and although Seche Vite or Poshe don't really alter the result, they don't make it better. Recently, a friend of mine sent me this fast drying Sally Hansen Topcoat, and she raved about how good it was for holographics. I was skeptical at first, but after I tried it, I really saw a difference. Now, it's not something that can be seen through a lense. Unfortunately, I don't have a side-by-side comparison to prove this, you're just going to have to trust me, just like I trusted my friend when she said it.
2 coats OPI Designer Series Glamour
Sally Hansen Diamond Flash Topcoat