If you just use it on a clean face it doesn't do much of anything, but I will give it credit for one thing...
- I give this a 5 for neutralizing redness and whatnot
- but I give it an 8 for oil control
I forgot to mention that, no, the colors do not show up on your face. You're not going to walk outside with a giant pink smear on your cheek and a chunk of yellow on your forehead lol.
You either swirl your brush in all four colors and apply to where it's needed (which is what I do) or you can, if you want, apply each individual color corrector to problem areas.
I've done both and either way they don't show. =]