reasonably common, my DH and son have blue/grey/green eyes that can change depending on the light they are in and on the colours that are in the environment around them
Will attempt a simplified explanation of the melanin distribution of different coloured eyes and why hazel/green ones are so prone to appearing different colours, but it gets a bit involved so might be worth you searching up about eye colouration genetics etc
Brown eyes have a large proportion of melanin, the coloured pigment, in the iris, blue/grey have little melanin
Hazel eyes/green eyes will have some variable amount of melanin within the iris but, the green or blue hues come from the visual effect of the scattering of light in the stroma (the fibrous tissue bundles you see radiating out from your pupil). This effect is called Tyndall scattering, and occurs when light passes through transparent matter and is scattered by particles smaller than the wavelength of visible light: similar to the phenomenon Rayleigh scattering which produces the blue colouration of the sky.
So the hazel/green eye color is caused primarily by interference effects rather than by pigment, and they can vary depending on the lighting conditions in a way that dark brown and blue eyes do not.
loving the turbans btw, think the red one does the most drama for your eyes