Option to make default colour schemes accessible?

[hadley]

It would be a shortcut for changing all of the default colour/fill scales.

[yutannihilation]

Related: #4466

[teunbrand]

Proposal in #5946 is to run this through the theme, so set_theme() can be used to change global defaults.

# From #5946
devtools::load_all("~/packages/ggplot2")
#> ℹ Loading ggplot2

set_theme(
  theme_gray() +
    theme(
      palette.colour.continuous = pal_div_gradient(),
      palette.colour.discrete = palette.colors(7)
    )
)

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

p + geom_point(aes(colour = class))

^{Created on 2024-06-21 with reprex v2.1.0}