ggplot2: How do I set the default fill-colour of geom_bar() in a theme [duplicate]

Question

I'd like to define a theme for ggplot2 so that the default colour of geom_bar() is not black.

How can I do this?

Answer 1

you can't do it in a theme (sadly).

You want to change the default settings of a geom,

  update_geom_defaults("bar",   list(fill = "red"))

and you can also change a default scale, e.g.

  scale_colour_continuous <- function(...) 
         scale_colour_gradient(low = "blue", high = "red", na.value="grey50", ...)

Answer 2

Theme controls apperance of non-data elements, so you need to work with scale functions. Try scale_fill_brewer, e.g.:

 scale_fill_brewer(palette = "Set1")

For details on this function see here.