It looks like in the new ggplot version 3 when you have an ordered factor the color is automatically viridis?
You can see the difference by uncommenting #d$group = as.character(d$group) in the code below.
With the change, if you don't want viridis now you have to use scale_color_manual and specify colors? That seems like a lot of work. Why not just leave the old colors?
The old way gave you default colors that were much more differentiated. Now with viridis it is hard to differentiate bars or points or whatever you are plotting.
Is scale color manual the only way around this? Seems like a ton of work every time you plot with ordered factors.
library(ggplot2) d=data.frame(group= letters[1:4],v=1:4) d$group = factor(d$group, levels= d$group, ordered = TRUE) #d$group = as.character(d$group) ggplot(d,aes(x = group, y =v,color =group,group = group))+geom_point()