Wink of Stella clear glitter brush pen but was very disappointed with the results. While you can see the glitter on a black background, it's not very visible on other colors. No matter how many times I apply the glitter, there's simply not enough.
Then I found out that Sakura gelly rolls also have a clear glitter pen. I promptly ordered a set (it comes in a 2 pack, very handy) since I absolutely love their metallic gel pens. These gel pens are the real deal - the glitter is clear so you can use it on top of any color. It doesn't disturb the color underneath, so use it over colored pencils, watercolor, ink or any other medium. Best of all, there is plenty of glitter to go around! In fact I had to use a small brush and push the glitter around since a little goes a long way with these pens.
Just remember that these supplies are for fun, none of them are archival or artist quality. The glitter will dry on the page but will come off if you rub it. I always put a piece of scrap paper in between the pages for a day or two to catch any excess pigment or glitter. After that I find that the color and glitter don't move around too much. But if something like that bothers you, you might want to avoid glitter and pastels.
The best part about these pens is that they don't cost very much. The 2 pack was just about $4 on Amazon while the Wink of Stella cost me more than $5 at Michaels and that was after a coupon! Overall I'd say that the clear glitter gelly rolls are the best way to add some sparkle to your coloring pages. Use them on eyes, lips, water bubbles, gems or anything else you want to highlight. Happy coloring (or should I say sparkling?) everyone!