Change ggplot2 colourbar tick marks to black

Question

In some of my plots I find it hard to see the tick marks in the colour bar. I haven\'t been able to find a documented way to change the colour of the ticks. All the examples

Answer 1

I usually find what I need to change by extensive use of str. I'm sure others can do it more elegantly.

g <- ggplotGrob(p)
g$grobs[[8]][[1]][[1]]$grobs[[5]]$gp$col <- "black"

library(grid)
grid.draw(g)