I'm generally a black sidewalk fan unless you have something to show, ie. "Goodyear, Michelin, etc." If you're going to show white sidewalls make sure that they are a major brand. No one cares to see your white wall Kumhos.
Just my opinion.
I will say that a nice white sidewall would probably look good on a white truck.
White Walls ? blah. White letters are okay. I always used to run white letter out, until I got tired of cleaning them all the time to keep them white. Blackwalls out IMHO, are the way to go. Easy-peasy.
Depends on the truck and the tires too. A TRD with meaty tires can look fine with white letters out but a limited or platinum with more of a street like tire doesn't look right.
I think Michelin makes great tires but their white lettering looks lame. It's just their name with nothing else. They should have used raised white letters for the model as well to make it look more balanced like the "LTX MS2" should also be raised white. I am guessing I will be getting Michelins once my oem BFG's wear out and for the reasons stated I will probably go black. Also just my 2 cents.
Blackwalls are rather "everyday", but then again some tires are not available in white letter, so it depends on what you want to run, and what detail your truck has.
White walls are plainly frumpy, especially the big wide ones, there is a guy running around here with a 2010 F150 (no, not an old classic) with wide stripe white walls similar to the one in the picture below, but with bright red old style steel wheels and chrome hub caps- crap is that MF ugly! But it is good for a laugh on a bad day.