Lucky Patsy's "Mom wrote:

Technique or style is not protected under copyright laws, so it is permissible to make a quilt inspired by Picasso's work or style because it will be substantially different from the original.

Not true. This is called "derivative work" and the copyright laws are very specific about it. You cannot just change colors or even the medium and be worry free. Here are some copyright myths explained.
http://www.templetons.com/brad/copymyths.html

Artists in all media have to expose their art to the public in order to eat. It's that simple. They have the right to be protected from those who copy their ideas and claim them as their own. Most of us will grant individuals sigular use of the work, be it a quilt pattern or graphic image or whatever, but you do not have the right to assume it has been granted just because we put it out to public view. To have your work copied without receiving acknowledgement for your efforts, be it financial or other recognition, is not a compliment. It is stealing.