Two pebbles dropped into a still pond produce waves that interfere with each other to form new patterns.
Light also has a wave nature.
Therefore, light from a distant source shining through the holes of a window screen produces an interference pattern which is similar to what would be seen if you could drop many pebbles simultaneously in a regular pattern on a pond. Sunlight is made up of many different colours, each of which has a different wavelength. Therefore such light will produce a multi-coloured terference pattern. This photo was taken through the screen window of a cottage. The rippling surface of a lake has produced a multitude of images of the sun, with each image resulting in a separate interference pattern.