I just put a State Bicycle Co. oil slick colored seatpost on my gravel cruiser, reversing on an earlier decision to avoid it, fearing it would be over-the-top. It still may be, but when I switched from the blue Supacaz saddle with the oil slick rails to an all black SQ Lab 611 Active, the black seatpost just made the top end feel too dull, ergo the SBC.
It does match up with the ColorFlow fenders really well, and i’ve got the matching SBC oil slick handlebar, so the whole thing is “of a piece,” as they say.