Nice sketch and colors. The Nick Mikey really is the best incarnation of his character along with the 1990 movie and Mirage versions.
Funny thing: I had just finished watching the latest episode of this before I checked dA.
You really captured Mikey's spirit in that expression, I gotta say. Impressed with the color, too; being that they usually work in low light it's not always easy to see, but I'm pretty sure that's exactly how he'd look in sunlight. Muy bueno!