Recent versions of Maya have changed the way icons appear in the outliner, which has made it sometimes difficult to find what you're looking for. Color Marker is a script that can help to make this easier. Created by Klaudio Ladavac, who also recently came up with a new wedge tool for Maya, the script lets you assign colors to the items in the outliner. This makes it easier to find what you're looking for when managing heavy scenes in Maya. You can also assign random colors to viewport items, such as the wireframes, locators, curves and deformers.
The latest version lets you quickly randomize wireframe color on selected objects in your scenes. Pick up a copy of Outliner Color Marker here.