In first image, its like a reflection of a image however the colors are different. On the left, it gives a feeling of cool, and on the right, its the opposite, it feels warm. In the second image, I see that the trees have same color, but the tree on left side, it appears more gray, and the tree on right side, it appears more green because of the surrounding color.
In the first picture, the red dots are being contrast. on the right, the red looks saturated because of the surrounding grays. On the left the dots look really bright and pure. However both red are exactly the same. In the second image the triangles are fading away on the right side while you can clearly see it on the right side. The green triangles are being simultaneous Contrasted.