I have the dash out on my 82 and have decided to change all the bulbs while it is apart.  I noticed today that there are two different color bulb sockets on the back of each of the gauge units.  Is there a difference in these two in regards to the bulbs or what is up with this.  Anything special to consider while I am doing this?

I'm not sure. I think I have seen black, white, grey, and blue sockets. Don't know if the actual color of the socket means anything or not.....might be interesting to see where this one(question) goes.
 Are yours the ones that just kinda screw into the panel, like 1/4 turn in/out?

Yes, all look to be the same ~1/4 turn sockets but two different colors.  I did not look to see if the colors might have any correlation to anything like gauges vs warning lights.  I'll look this weekend. Are all the bulbs the same regardless of where they go?

I recently replaced all of my bulbs and noticed that I have both gray and blue bulb sockets.  They are the 1/4 turn type and are the  same size.  The same bulb fits in them regardless of color.

This is a fun question are the colors for the application: instrument lights Warning lights ( fuel gen etc) or is it size I think their is at least two size holes 5/8" and 1/2"

I replaced mine forgot where the resistors went on gauge back so I went to a local and asked him to look at the back of some units.   Long story they all had different colors in different place few were the same.  So I would guess it does not make any difference.  Do you have all of them? let me know if you do not I may have a couple hanging around you could have.

In an email I gave you a site I used I just posted it again just in case people following this post need it.  I believe the lights are 194 check this site for the best buy on lights. http://www.memotronics.com/ .   just type in the number. 

By the way the top light the one that is connected to the vary top of the console is suppose to be a different bulb.  Does anyone know if that is true or not and if it is true what is the bulb number .  By the way I have a pdf on light type with that base in case you decide to go a little brighter or for a little longer life bulb.

 I will send it if you want it or post it if someone will tell me how to post a pdf.

I did all my bulbs and ordered new sockets. Corvette America only sells one kind and told me they were both the same.

Thanks I guess it is just a rummer until someone has some proof.  I have not found any that were different.  I have found that the heat from that top bulb seems to warp the plastic on all of the consoles I have checked.

Gil,

YA gotta be careful with this type of bulb. Ya don't wanna replace a bulb with one of a higher candlepower rating, as it can(and usually will) wind up melting stuff.
On the older, non-circuit board gauge clusters, the bulbs are different...they're like regular bulbs, with a metal base. The push-in kind like the 75-up cars have can be replaced with bulbs of much higher candlepower....that means more heat...sometimes more heat than the circuit board, or the surrounding plastic can handle.
If you are replacing the bulbs, be sure to match the factory ratings on candlepower. Just because the bulb looks the same, and plugs in does NOT mean it is the same. Get a magnifying glass or something and look at the bulb(s) to be sure what they are rated for.