`element_markdown()` not working with `axis.title`

[maia-sh]

Thank you for this wonderful package! I am trying to add colors with html to title and axis labels. plot.title = element_markdown() works, however axis.title = element_markdown() does not. Based on the element_markdown() document I believe this should work for all text.

---

library(dplyr)
library(ggplot2)
library(ggtext)

mtcars %>% 
  ggplot(aes(x = mpg, y = cyl)) +
  geom_point() +
  labs(
    title = "I <span style='color:blue'>love</span> cars",
    x = "Look at this <span style='color:red'>mpg</span>!"
  ) +
  theme(
    plot.title = element_markdown(),
    axis.title = element_markdown()
  )

^{Created on 2021-02-10 by the reprex package (v0.3.0)}

[delabj]

It looks like you can solve this particular issue by specifying the axis you want to change like this.

library(dplyr)
library(ggplot2)
library(ggtext)

mtcars %>% 
  ggplot(aes(x = mpg, y = cyl)) +
  geom_point() +
  labs(
    title = "I <span style='color:blue'>love</span> cars",
    x = "Look at this <span style='color:red'>mpg</span>!"
  ) +
  theme(
    plot.title = element_markdown(),
    axis.title.x = element_markdown()
  )