Weight painting problem

I can’t understand how can I reduce weight in weight paint mode. I can only paint blue areas until they are red. How can I make red areas into blue?

The only things that are doing something in paint toolbar are opacity and size. Other buttons (and color) doesen’t affect the paint process at all…

Not that I tried it, but look at the bottom of this page:

http://www.blender.org/modules/documentation/htmlI/x7214.html

Hopefully its correct.

you need to set your target weight for the group you are painting in the vertice group buttons, then paint.