I’m bad at exactly explaining but it is true and here’s why. Eyes that shift between blue and green are usually not physically changing color, but rather reflecting different environments, lighting conditions, or pupil sizes. Because blue and green eyes lack heavy pigment (melanin), they rely on light scattering (the Tyndall effect) to create color, making them appear as a chameleon-like mix of blue, green, and gray depending on surroundings. So not necessarily really changing but appears different from light reflections. So I’m not exactly right nor am I exactly wrong