Continuous contrast refers to the phenomenon of color contrast and visual errors observed and felt by the human eye in different periods of time. Continuous contrast is divided into two types of positive afterimage and negative afterimage. Positive afterimage refers to the fact that after the visual stimulus of the object stops, the vision is still temporarily Preserve the visual state of the original object image. Negative afterimage means that after stopping the visual stimulus of the object, the vision still temporarily retains the complementary color with the original object (such as red and green, blue and orange, yellow and purple, etc. ). Visual state. According to the above definition, Which of the following are negative afterimages:. ['The static picture is continuously projected at 24 frames per second, and a dynamic picture will be formed in front of the eyes.', 'After staring at a red object, even if you remove the object, you will still feel red in front of you.', 'After viewing red for a long time, when you quickly move your vision to white, you see not white but green.', 'Red and yellow are matched, and the eyes sometimes feel red as a purple color, and sometimes yellow as a green color.']