a month ago i was looking for answers on how to change that annoying blue background when X starts in RedHat 9 which sometimes doesn't fit with your theme, and i thought i might share what i've found. i know RedHat 9 is kinda defunct, but i do know there are still a lot of Linux users who haven't upgraded to Fedora or switched to another distro. that includes me!

the line "xsetroot -solid 'COLOR'" sets the background color at start.

go to these files and edit accordingly. #5477A0 is the blue color.

/etc/X11/Xsession
EDIT LINE: xsetroot -solid '#5477A0'

/etc/X11/Xsetup_0
EDIT LINE: /usr/X11R6/bin/xsetroot -solid "#5477A0"

(/etc/X11/gdm/Init/Default
Default: symbolic link to ../../xdm/Xsetup_0) <-- this one is just a link to the file above

having changed all these to the color i wanted, it worked for GNOME as WM. but when i shift to KDE i still got the blue background after i've logged in. i never bothered to change this. so last night while i was tinkering around my Linux i found the answer to why i still have that background!

editing the file below will rid you of that blue background.

/usr/bin/startkde
EDIT LINE: #test "$XDM_MANAGED" || bkg="-solid #5477A0"