How do I change rxvt colors to white on black?

Note: Updated answer to include desktops like GNOME and LXDE that do not load .Xresources or .Xdefault files by default. Also updated for packages rxvt-unicode and rxvt differences.

You can launch it with the command in a terminal window:

rxvt -fg white -bg black

which sets the foreground to white and the background to black.

Or you can launch it using Alt+F2 and typing it in:

Either way listed above should give you a rxvt terminal that looks like this:

To make it permanent, you can add the following lines to the end of your ~/.Xdefaults or ~/.Xresources file:

Very important:

If you installed rxvt-unicode add these lines to your .Xresources file:

URxvt*background: black
URxvt*foreground: white

If you installed just rxvt add these lines:

Rxvt*background: black
Rxvt*foreground: white

URxvt can support more fonts.

If you wanted to use a Monospace 9 font with urxvt, add a line like this:

URxvt*font: xft:Monospace:size=9:antialias=true

Or you can use fc-list | sort to list all fonts available, then you can find one you want and set it like this:

URxvt*font: xft:DejaVu Sans Mono:size=9:antialias=true
URxvt*boldfont: xft:DejaVu Sans Mono:bold:size=9:antialias=true

Rxvt has limited font support.

If you run the command xlsfonts from a terminal window, it shows you all the fonts that can be loaded by rxvt instead of urxvt. Here is some examples:

xlsfonts | less

The list will look something like this (truncating for space):

-arabic-newspaper-medium-r-normal--0-0-100-100-p-0-iso10646-1
-arabic-newspaper-medium-r-normal--32-246-100-100-p-137-iso10646-1
-bitstream-bitstream charter-bold-i-normal--0-0-0-0-p-0-adobe-standard
-bitstream-bitstream charter-bold-i-normal--0-0-0-0-p-0-ascii-0
-bitstream-bitstream charter-bold-i-normal--0-0-0-0-p-0-iso10646-1
-bitstream-bitstream charter-bold-i-normal--0-0-0-0-p-0-iso8859-1
-bitstream-bitstream charter-bold-r-normal--0-0-0-0-p-0-adobe-standard
-bitstream-bitstream charter-bold-r-normal--0-0-0-0-p-0-ascii-0
-bitstream-bitstream charter-bold-r-normal--0-0-0-0-p-0-iso10646-1

Or you can find a font you want using xfontsel and select all the settings you want and it will create the line you add like this:

You will just have to play around till you find one you like.

Add that line to your .Xresources file.

Rxvt*font: -misc-fixed-medium-r-normal--13-120-75-75-c-70-iso8859-1

Anytime you .Xdefaults or .Xresources file(s), reload them with the following command(s) from a terminal window (requires restart of rxvt terminal if you are using it):

xrdb -load ~/.Xdefaults

or

xrdb -load ~/.Xresources

Note: If you have a desktop like LXDE installed, these files do not load by default, but if you create ~/.xinitrc with using which ever file you want as either .Xresources (recommended) or .Xdefaults and add the following line to the file:

xrdb -load ~/.Xresources &

Then make the .xinitrc executable:

chmod +x ~/.xinitrc

Reboot, then all you have to do is launch rxvt as normal.

Screenshot from LXDE VM

Hope this helps!