This is about primality. In the top panel, drips of paint run upwards to the top edge. The only colours used are the three (subtractive) primary colours: cyan, magenta and yellow. The colours randomly coalesce and self-mix to form secondary and tertiary composite colours. In the bottom panel, the Sieve of Eratosthenes is used to calculate the prime numbers between 1 and 99. All positive integers can be factorized into their underlying prime numbers; all colours can be broken down into primary colours. The mixing of the colours is the multiplication of the prime numbers.

As the colours mix they become darker and less saturated, so the middle of the painting comes forward and the top recedes. From a distance it looks like tall buildings in the distance, with psychedelic multicoloured rain pouring straight down.