top is from ford ecosport

left, honda city

right, suzuki jimny. bago pa oil so it's not dark

city and jimny produce brown hues. but the ecosport always makes it reddish i've tried different brands of oil, they all eventually become reddish

in case anyone is wondering. the ecosport's oil always starts out amber colored just like when you pour it out from the jug. then over time it gets reddish. always been like this since brand-new.

anyone's got any explanations?