The colors come from thin-film interference — light reflecting off the front and back of an oil film, some wavelengths adding, others cancelling. That's classical wave optics; an oil slick needs no quantum mechanics.
What's real is the formalism. Interference is what you get by adding amplitudes and squaring them into a probability — the Born rule, P = |ψ|² — and a two-path film is mathematically identical to the double-slit, a Mach–Zehnder interferometer, or a single qubit's phase. Fire single photons through a real film and their odds of landing "bright" trace the curve this shader draws. (Coherence fading to gray is decoherence; hover-to-measure is which-path complementarity.)
What it isn't: no qubits, no hardware, no entanglement — and interference alone isn't proof of quantumness. Honest description: a classical instrument built on the quantum interference formalism.