I am sure that at some time you misread the instructions for a card challenge. This is the second time that it has happened to me. I thought we were supposed to use a primary color and it's complimentary color. I dove in and made the "mistake" card. The image is from http://freevintagedigistamps.blogspot.com. I think I am going to save this one for my DH.
The real challenge is to use 2 or more complimentary) colors so I made the first card. I am kinda liking the off center circle thing at the moment so I did that here.