How Do I Alien skin tone

You'll need to have a paint program. For changing a skin tone, you can probably get away with using Microsoft Paint (that comes with all the Microsoft operating systems.) For doing a mask, you'll probably want something a little less clumsy such as one of the real graphics programs like Adobe Photoshop, Paint Shop Pro, Corel Painter 8 or a free one like GIMP.

The official websites all have downloadable, free trial period versions:

http://www.adobe.com/homepage.html

http://www.jasc.com/products/paintshoppro/

http://www.corel.com/servlet/Satellite?pagename=Corel2/Products/Home&pid=1047022702185



This one is shareware:

http://www.gimp.org/

with some further instructions/help: http://www2.arnes.si/~sopjsimo/gimp/stable.html, http://www2.arnes.si/~sopjsimo/gimp/faq.html



This one has links to several free products:

http://www.a1b2c3.com/free/av09.htm

Then you need tutorials:
http://thesims2.ea.com/help/ (has a list with several of the tutorials)

http://members.fortunecity.com/lpx/tutorials/hair.html

http://www.geocities.com/thisday2005/tutorial.html

http://home.planet.nl/~Dobbe065/Tutorials/Denim1.html

http://members.fortunecity.com/lpx/tutorials/bumpmap.html

http://www.jedifiction.com/simsstuff/tutorials2.html


These tutorials cover all sorts of aspects of how to use Body Shop. I know that one of them shows how to access the skin files so that you can change them. (I believe it is the tattoo one that does that.)