Sidebar arrow colors for discrete color maps

I am using psscale to create a color scale for the ‘mag’ color map. I have set the foreground and background colors, but the sidebar arrows are the default black and white. Can I change the colors of the arrows with a discrete color map like ‘mag’, or is that only available for continuous color maps?


Hello @bar,

welcome to the GMT forum :slightly_smiling_face:!

I am wondering whether -M is missing when you set up your colormap via makecpt (

If you can provide a code example (and the required input data), it will be easier for people to help you. You can format your script as code by placing three backticks in the line before and after the block with the script:

your script formated as code

Adding -M to the makecpt command worked. Thank you for the help and welcome!