only the quality of the drained oil can not tell about its self, it may simply mean that the oil has done nothing to prevent the damage in engine so its still fresh.
For example a thick oil may come out fresh because it simply can enter the tight spaces in engine so it got less beating than thin oil.
Oil grade which is recommended by the makers of the machine also depends on the space between different components for eg, space between rings and cylinder. Gap between the contact surface of 2 sprockets etc