Paul,
I’m in a similar situation: I’m using plot(marginal_effects(fit), theme_theme_tufte()), but then I’d also like to change the color of the line which defaults to blue. I’ve tried lots of combinations by now (using different ggplot2 calls, or even using par() directly), but alas, it’s still blue. Not that I don’t like blue, it’s just that all my plots are in bayesplot::color_scheme_set(“darkgray”) :(