Could colour bar guide ticks be more readable? about ggplot2 HOT 3 CLOSED

Some of these already have solutions.
To just put ticks on one side of the colourbar, set the size to 0 for one of the ticks:

library(ggplot2)

p <- ggplot(mpg, aes(displ, hwy, colour = cty)) +
  geom_point()

p + theme(legend.ticks.length = rel(c(0.2, 0)))

To put ticks outside the bar, use negative tick lengths. If you make them too long, you might manually need to set the text margin for proper spacing.
I'm overriding legend.ticks because white ticks can't be seen on white background.

p + theme(legend.ticks.length = rel(-0.2)),
          legend.ticks = element_line())

^{Created on 2024-04-22 with reprex v2.1.0}

from ggplot2.

Changing these defaults will probably affect a lot of people's plots, so I'd rather refrain from that unless there is an objective improvement to be made. Stylistic sensibility varies from person to person, so let's leave this as is for now.

from ggplot2.

Aha, thanks @teunbrand !

Feel free to close, if you think defaults should stay as is

from ggplot2.