Colours not always in correct order by default

[alice-hannah]

For example:

Colour order correct in legend but not in order of bars. (Correct order is dark blue, turquoise, purple). It may be difficult to control colour order using sgplot, but is there anything we could do to make this easier for users? Or to draw people's attention to this?

[alice-hannah]

Code for example:

library(ggplot2)
library(dplyr)
library(sgplot)

d <- subset(mpg, manufacturer == "ford")

ggplot(d, aes(x = model, fill = class)) +
  geom_bar() +
  scale_fill_discrete_sg()