VS 2008 How can I fill color in part of image?

Hello,

Does someone have some sample code to show how to fill in a color of part of an image to the border? I have a white background image with black lines drawn as a head with hair outlined. i want to fill in the face with a skin color selected and then the same with the hair. How can i do this in asp.net on the server side? I will be returning the image after it has been modified.

Thanks!