The Hitchcock film with the single color gunshot was not NOTORIOUS but SPELLBOUND. (Are there any prints available that preserve this?) A number of B&W films from the thirties had brief color sequences, including THE WOMEN, PORTRAIT OF JENNY, and the original version of THE SECRET GARDEN (and let's not forget THE WIZARD OF OZ!). In regard to SCHINDLER'S LIST, the red coat may come close to stretching the limit, but it can be justified on two grounds: 1) that it provides an anchor for individual experience in the face of mass suffering, and 2) eventually that little girl dies with the rest--the red coat is last seen on a cart of dead bodies. In other words, it attempts to give a human dimension to a massacre. Whether it works or not is a point for debate (Siskel and Ebert split on that one question also). The scene that is not noted is the colored flames in the lighting of the Sabbath candles--that, I think, is the most effective use of color, the literal rekindling of an almost extinguished faith.