Snow Golem's Heads Changing Color

Sometimes my snow golem’s pumpkin heads start flickering from orange to dark orange or brown or black. Recently they’ve started turning other colors too, like lime green or yellow or red. I’m pretty sure the pumpkin heads are just supposed to stay orange. I don’t think there are any specific circumstances that this happens in, just with any snow golem that has a pumpkin on its head. It happens more often when the snow golems are in my peripheral vision than the ones I’m looking at directly though (though occasionally it happens then too).