Does MPB prone hair tend to lose its richness of color/get lighter? (I have dark brown hair)

Was just wondering , is this a natural occurrence?

Anyone know if this is the case?

yeah, this is a part of miniaturization. the hair also gets thinner (you probably know this though)

but one thing i'd consider is that if you're doing a lot of topicals then that can affect the colour of your hair. apple cider vinegar, for example, is a natural hair lightener, and after spraying it on my head and leaving it on overnight for a few days i noticed that i'd given myself some little blonde tips. i don't mind it though

Yes. I noticed my hair was lighter in colour, thin, frizzy and dry. In my case treating micro nutrient deficiencies and malassezia works well.