COLOR ILLUSIONS

The red glasses in the right columns appear to be different in color from those in the left ones, though they are identical.

BLUE DAY & NIGHT - THE BLUE COLORS ARE THE SAME IN EITHER HALF OF THE IMAGE.

There appear to be spirals of two different types of red. Actually, they are identical.

There appear to be spirals of two different types of green. Actually, they are identical.

The red is homogeneous over the figure, but appears to be red-purple behind blue lines or to be orange behind yellow lines.

Red appears to be magenta or orange though they are the same.