I think we obsess too much (me included) about getting every drop of the old oil out when the reality is you can't, there will always be some left in bearings and oil galleries. In any case the colour of the oil is not a good guide to to the oils condition, ask any diesel owner 2 mins after they have done an oil change. Petrol owners should have pretty clean oil after a change if they don't then they didn't get enough of the old oil out. In 10 years of using a pump to change the oil, only once did I not achieve visibly clean oil after a change but it will have done no harm if 95% of the oil was new.