Are the pushbuttons supposed to be backlit on 2nd gen panels?

I never really paid attention when my truck was new, but which buttons and switches are supposed to be backlit? Because right now, the only ones that are backlit are my rear diff lock button and my drivers window button (the one that reads "auto"), and my stereo and climate control console. I've had my truck for 5 years now and it's getting up there in miles, so it could be that the other backlights are all just burned out, but I can't remember if they were ever even lit at one point. I'm talking about fog light button, the AC power outlet button, downhill assist button, the sideview mirror adjustment buttons, and the transfer selector dial right of the steering column. And maybe some others that I am forgetting. Are any of these supposed to be backlit??

 

mine are like tht too

 

mines an 06 and mine lights are variable sometimes off sometime on the only consistent one is the power outlet