We discuss how Victor Vasarely used the idea of “program” to define his works, making him a visionary in the potentials of using coding for the practical production and social impact of art, well before the emergence of computers as tools in the hands of artists. We analyze the color patterns in his painting "Bull". We show the hidden and “almost regular” structure in the color usage, and ponder about the reason behind the minor deviation from the perfect regularity: a conscious choice, or a mistake in execution?