Don't worry about that - it is nothing new.
5 years or so ago, I broke/dislocated the 2nd toe on my right foot playing softball. There's a story about that, but I'll skip it this time. The end result (even with physical therapy) was that the middle joint will not bend much at all. Doesn't hurt - that is just the way it is.
So, that last root-kick I did at the Camp Croft Half Saturday around mile 12 that almost stopped me in my tracks? Yep - that was the toe that took the brunt of it. That afternoon it was already turning colors. Purple at the bottom of the nail, then a light brown color with a darker ring at the joint. Hurts a bit to the touch, but I think the fact that it doesn't bend, even though that likely played a part in it hurting Saturday, also makes it not hurt when I walk. I barely feel it - so that is just fine!
BUT - the bottom (outside) part of that same foot is sore to even walk on. Started Sunday, and made me skip my run this morning. Heading to Chicago tomorrow until Friday morning, with likely very little time to run anyway, so I may have another 5-6 days off in a row. Can't say I like the sound of that. Bringing some treadmill-ready running clothes just in case I feel better. 10+ hours a day on my feet may not help the situation though (working a booth at Greenbuild).
Still have 2 weeks to register for Paris Mtn 20k and ~3 weeks before Harbison 50k. (To beat the early entry fees anyway!).