Many years ago my wife owned a 1990 Mazda Protege that I maintained DIY 3K mile oil changes using Mineral based Valvoline. That little car ran like a sewing machine but out of all the car I have owned the last 40 years that Mazda with the Valvoline always had clear new looking oil on the dip stick. Shortly after on some other car or truck early 90's I used Castrol GTX and the oil would turn black before I backed out of the driveway.
Thinking back to that Mazda I always wondered was that car that clean running or was the oil that good or was the oil that bad and didn't remove any dirt so the oil stayed clear?
Regardless, I have owned many cars and never had oil stay clean 3K miles except for that one Mazda.. OP yours looks great!