If you include that code in usersetup.mel, it'll be run as part of the startup procedure. But this probably doesn't work, since creating a new document happens after all the initialization, and would overwrite any effects.
scriptJob does nicely for "do this every time something happens" stuff -- like every time I start a new document.
Try this: (haven't tested it -- I'm not in front of Maya)
global proc setupLambert1() {
setAttr "lambert1.color" -type double3 1 1 1 ;
setAttr "lambert1.transparency" -type double3 0.18182 0.18182 0.18182 ;
}
scriptJob -e "NewSceneOpened" "setupLambert1";
Put that in usersetup.mel -- in your scripts dir -- My Documents/Maya/scripts/ -- and it'll take care of it.
I've broken one of the cardinal rules of scriptJobs though. I haven't given it a parent or any way to kill it. So, it'll do it every time a new document is opened -- whether you like it or not. If you ever want to disable it, comment out the scriptJob line, or rename usersetup.mel and restart Maya. Or delete the scriptJob manually.
Rob Richardson