Tukukkk

I'm trying to make a density plot in ggplot with different colors based on one cutoff. There are a couple questions floating around about how to conditionally color histograms based on a cutoff, and how to color the quantiles on a density plot. However, I haven't found any resources on how to color a density plot given a single cutoff. Here is my code so far:

ggplot(dde_test, aes(x = meanABC)) +

          geom_vline(aes(xintercept=quantile(dde_test$meanABC)[4]), color="black", linetype="dashed", size=1) + 

          geom_density(alpha = 0.7, color = "black", fill = "#cb351e") + #, fill = "#405484"

          scale_x_continuous(limits = c(3,12), expand = c(0, 0)) +

          scale_y_continuous(limits = c(0,0.3), expand = c(0, 0)) +

          xlab("") + 

          ylab("density") +

          theme_bw() + 

          theme(panel.border = element_blank(), panel.grid.major = element_blank(),

              panel.grid.minor = element_blank(), axis.line = element_line(colour = "black"))

which produces the following plot:

Very simply, I'd like to color everything above the dashed line red, and everything below it blue. I tried putting an if else statement in the fill part of geom_density(), but that didn't work. Any tips would be much appreciated- thank you!

p.s. I'd also like to keep the dashed line black throughout the plot; right now it's blending with the red density- would be great to get pointers on this as well. Apologies if these questions are very basic!

EDIT: I've seen this question before- Shading a kernel density plot between two points. but it's not the same as it isn't using geom_density. It's also coloring between two points, whereas I want to color before and after a single point.