So whatever your projects are – whether it’s for blockbuster films, 3D gaming, print, broadcast, product design or any other professional arts application, Maya 6.5 promises most powerful and superior tools and enhancements in industry today to empower you to be as creative as you can be and to bring your very own visions to life.

Now for final part, you may choose to use either Freehand Selection toll in Smart Edge mode or you may opt to use Magic Wand. Set Feather to about 1 pixel, and select one of faces. Once done, click on Flood Fill tool and set Blend Mode to Color in toolbar at top of screen. For a typical Caucasian skin tone, set Red, Green, and Blue levels to about 215, 190, and 150, respectively, then click OK. Now click Flood Fill to colorize selected face. You can repeat this process for all of skin in image.

Then select clothing and background and add color to as much or as little as you wish. When you're done with image, you might want to adjust overall intensity of colorization. To do that, make sure Layer Palette is open (if it isn't, choose View, Palettes, Layers) and then double-click on Copy of Background layer--this is one on top that we've been painting. Then you can use Opacity slider in layer's dialog box to change color effect. When you're satisfied, click OK to keep your changes.

Above simple instructions from Dave Johnson is very easy to follow and is very helpful for particular purpose.