How can one search in O(log n) time in a red-black tree?

How does the search operation for a red-black tree work and how does it take $O(\log n)$ time, where $n$ is the number of items? I know a red-black tree takes $O(\log n)$ recolorings and $O(1)$ rotations, but I was specifically interested in a good description of its search operation.

• If you're wondering how red-black trees manage $O(\log n)$ depth, you might want to look into 2-3-4 trees. Red-black trees are 2-3-4 trees in disguise. – Pseudonym Sep 30 '14 at 5:04