How to draw the terrain of a specified area

[ximoge]

In a large area map, how to draw the terrain of a specified area in it, with other areas shown in gray.
For example, I’d like to only want to map the United States in colored topography, and map its neighboring Canada and Mexico in gray.

gmt coast -R-130/-70/25/60 -JL-100/35/33/45/12c -Baf  -Dl -N1/thick,red -N2/thin -A5000 -Wthinnest,white -Sblue -Ggray
gmt clip -JL-100/35/33/45/12c -RUS -T
gmt grdimage  @earth_relief_30m  -JL-100/35/33/45/12c -R-130/-70/25/60
gmt clip -C
gmt end show

The result is as follows:

But the result I want is similar to this picture：

How to do it?

[yvonnefroehlich]

Hello @ximoge,

I am wondering if using the -E flag of coast would be easier here instead of clip:

gmt begin usa_dcw_mx_ca png
	gmt grdimage @earth_relief_30m -R-130/-70/25/60 -JL-100/35/33/45/12c
	gmt coast -Baf -Dl -N1/thick,red -N2/thin -A5000 -Wthinnest,white -Sblue -EMX+ggray -ECA+ggray
gmt end show

[Joaquim]

See also coast -E+c|C