Are switchblades legal to carry in Oregon?

Yes switchblade's are illegal in Colorado as is any knife that is assisted opening such as a gravity knife like the butterfly knife or is assisted with a spring or lever.

This is not completely true. A knife that is "spring assisted" is legal as long as you have to have direct contact with the blade to open it (such as those that have a small nub on the back of the blade, or those that have a thumb nub), while "spring loaded" or "automatic" (as stated above) are illegal. Many knife makers such as Kershaw have spring "assisted" knives that are completely legal in Colorado.