How can I take indoor photographs where black people don't come out so dark?

I used forced flash and automatic function with no luck!

Having read through the appropriate parts of the user manual for this camera I can not find any way to adjust the color for improved skin coloration for darker skin. You might try setting the flash to higher output. That is explained on page 95 of your user manual.

Otherwise, the only suggestion I can come up with is to try a Canon camera with the My Colors option. Be sure to try the camera out to see if it does what you need. What you are looking for is the Darker/Lighter Skin Tones setting under My Colors (Color Accent on some cameras). Some Canons only have a subset of these My Colors settings so be sure to check carefully to get the Skin Tones option. I'm sorry I have not been able to come up with a list of which cameras have this, so you'll either have to look camera by camera on the Canon website (www.canonusa.com) or go to a camera store which sells Canons and has good sales persons.

Just a suggestion:
Don't use a stark white or really bright/reflective color as a background, the high contrast might cause problems.
and, don't use too dark a background either, it might cause a problem with not enough contrast.
Soft non-reflective mid-tones have worked best for me.

I would manipulate the photos with an editor, like PhotoShop.