For casual wear, it all depends on what the weather is, and how my feet are feeling. Sometimes, I'll do leather Teva sandals that have a mostly closed toe configuration, other times, I'll wear a pair of trail running shoes, or my Doc Martens 8-eyelet boots. The latter, usually with dark kilt hose. Only times I do the off-white is either with the sandals or the trail runners, since they don't seem to go well with black boots. Too much of a contrast. I sometimes wear a pair of dark brown casual shoes, usually with oatmeal kilt hose...
-J