Tama Kanematsu and Kowa Koida : “White + Gray = Red”. Japan
This illusion induces creates the appearance of red lines by putting white edges around the gray lines against a cyan background. The gray lines without the white edges do not seem red. If you cannot see the illusion, please step back from your screen until the white and gray lines are barely distinguishable, since the illusion requires narrow lines.
White + Gray = Red,

