What can you see? The Bezold effect is named after the German meteorologist Wilhem von Bezold (1837 – 1907). It shows that colors appear differently, depending on their surrounding colors. The red lines appears brighter in the white environment (left) than in the black environment (right). This phenomenon is called “assimilation”, since the red lines become similar to the black lines between them.

For me personally, this effect is less clear than in comparable arrangements (White’s illusion, Munker illusion)

What can you do?  Of course, when it comes to color assimilation, the most exciting thing is to vary the colors of the long lines or the short lines. I used the HSV model as a basis. Accordingly, you can specify the three values for the long lines (h_long, s_long, v_long) and the short lines (h_short, s_short, v_short) separately. The short lines can be lengthened or shortened with right_x_start. You can change the width of the lines as well. So you can reproduce the image above and you can examine the influence of single variables or their combination.

Related topics: White’s illusion, White’s illusion with dots, Munker illusion