How do I plot a solid colour throughout a whole figure?

I’d want to use a solid colour to fill my whole map figure so that I may use it as a background for my map. How would I go about doing this?

Add +gcolor to the frame setting is a basic function of popular option -B.

Welcome to the community! Below is an example of how to use +gcolor for a background color.

gmt begin ex png
gmt basemap -R0/10/0/10 -JX6c -Bafg -BWESN+glightblue
gmt end show