Here is one, why do you think oil is "dirty"? Since you like Toyo filters, maybe that is one reason (out of many) that is why your oil is getting blacker, if that is a bad thing let me know. Oil color means zero but use a better filter man. Toyo filter are about as good as Ghetto-marts. Serious pull them apart and look at them. 99% the same and one is 30+% cheaper.
Oil color is a funny thing. Do NOT go by color. Means nothing on oil longevity, perform etc. You are guessing going by color unless it is white. If you are not using UOA, there are other ways to "guess better" then just looking at "dirty" oil. Case in point, I have jet black oil perform great in UOA and very clear poorly.
Also I can have my Amsoil come out clear in 8,000 drains if I used these low drains. Does that mean my engine is clean, no. I can add LC20 to the oil and within 200 miles the oil is black. Does that mean it is bad? It is cleaning, function of Lc, but I do not know the oil is dirty etc since I have no clue on UOA. I know now my engine is as clean as I can get it. Some group 4/5 synthetic clean a little via there ester bases (redline, Amsoil, mobil) but it will take like forever to clean an entire engine. The % is too low to do much cleaning. It will clean but retain much better i feel.