The phrase "pink sheets" refers to the listing of stocks on the over-the-counter market. It is an informal term used to describe stocks that are not listed on major stock exchanges like the New York Stock Exchange or NASDAQ.
A more balanced approach will reveal to you what are pink sheets without the dismissal. (stockrockandroll.com)
Nothing wrong with pink sheet penny stocks if you know how to pick apart financial statements; otherwise quite hazardous as this area is rife with adverse selection. (ultimibarbarorum.com)