ggplot: colour points by groups based on user defined colours

Question

I am trying to define the colours of groups of points plotted in ggplot. I adapted code from this post:

Color ggplot points based on defined color codes

but

Answer 1

It works if you use unique and as.character:

ggplot(data = df, aes(col, D, colour = zone))+ 
  geom_point() +
  scale_colour_manual(breaks = df$zone, 
                      values = unique(as.character(df$color.codes)))