I've been following the instructions on Arch Wiki for theming the XScreenSaver's login window. I created a ~/.Xresources file, pasted this code taken (and modified) from the wiki:! xscreensaver ---------------------------------------------------------------!font settingsxscreensaver.Dialog.headingFont:        -*-dina-bold-r-*-*-12-*-*-*-*-*-*-*xscreensaver.Dialog.bodyFont:           -*-dina-medium-r-*-*-12-*-*-*-*-*-*-*xscreensaver.Dialog.labelFont:          -*-dina-medium-r-*-*-12-*-*-*-*-*-*-*xscreensaver.Dialog.unameFont:          -*-dina-medium-r-*-*-12-*-*-*-*-*-*-*xscreensaver.Dialog.buttonFont:         -*-dina-bold-r-*-*-12-*-*-*-*-*-*-*xscreensaver.Dialog.dateFont:           -*-dina-medium-r-*-*-12-*-*-*-*-*-*-*xscreensaver.passwd.passwdFont:         -*-dina-bold-r-*-*-12-*-*-*-*-*-*-*!general dialog box (affects main hostname, username, password text)xscreensaver.Dialog.foreground:         #ffffffxscreensaver.Dialog.background:         #ff0000xscreensaver.Dialog.topShadowColor:     #111111xscreensaver.Dialog.bottomShadowColor:  #111111xscreensaver.Dialog.Button.foreground:  #666666xscreensaver.Dialog.Button.background:  #ffffff!username/password input box and date text colourxscreensaver.Dialog.text.foreground:    #666666xscreensaver.Dialog.text.background:    #ffffffxscreensaver.Dialog.internalBorderWidth:24xscreensaver.Dialog.borderWidth:        20xscreensaver.Dialog.shadowThickness:    2!timeout bar (background is actually determined by Dialog.text.background)xscreensaver.passwd.thermometer.foreground:  #ff0000xscreensaver.passwd.thermometer.background:  #000000xscreensaver.passwd.thermometer.width:       8!datestamp format--see the strftime(3) manual page for detailsxscreensaver.dateFormat:    %I:%M%P %a %b %d, %YI've set the background to bright red just so I could confirm that it works, but it doesn't. I ran:xrdb ~/.Xresourcesandxrdb -merge ~/.Xresourcesbut still no changes were visible on the screensaver's login panel, still the same old ugly 
Customizing XScreenSaver login
x resources;xscreensaver