Hi Luigi, As you map z to colour, you need scale_colour_brewer, not the fill version. And to get discrete colours, you need to make z discrete. A separate group mapping isn't needed in this case. Try this:
ggplot(df, aes(x=x, y=y, colour=factor(z))) + geom_point(size=4) + scale_colour_brewer(palette = "Paired") Best, Mikko -----Original Message----- From: R-help <r-help-boun...@r-project.org> On Behalf Of Luigi Marongiu Sent: Thursday, 14 August 2025 06:25 To: r-help <r-help@r-project.org> Subject: [R] How to use RColorBrewer in ggplot2? Hello, I would like to define a color range to custom color some plot, specifically made in ggplot2 (but also for normal plots). I have been trying to use RColorBrewer but I don't get any value out of this function. I expected it would create a vector of color values, but I must be missing something. What is the correct you of this function? Thank you. EXAMPLE ``` set.seed(50) df = data.frame(x = runif(15, 0, 1), y = x^2 + runif(15, 0, 1), z = rep(1:5, 3)) library(ggplot2) library(RColorBrewer) ggplot(df, aes(x=x, y=y, colour=z, group=z)) + geom_point(size=4) + scale_fill_brewer(palette = "Paired") ``` -- Best regards, Luigi ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide https://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. This e-mail transmission may contain confidential or legally privileged information that is intended only for the individual or entity named in the e-mail address. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or reliance upon the contents of this e-mail is strictly prohibited. If you have received this e-mail transmission in error, please reply to the sender, so that they can arrange for proper delivery, and then please delete the message from your computer systems. Thank you. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide https://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.