Coconut oil easily changes its color depending on the room temperature and solidifies very easily. When it does, the color changes to a whiter look. The color change is completely normal when the coconut oil is pure and does not contain other artificial ingredients.
This switching back and forth from solid (white) to liquid (clear) and then back again does not harm coconut oil. In fact, coconut oil is highly resistant to rancidity, perhaps more resistant than any other fat on the planet.