Hi new here. For about month now I have gotten dark brown coloring on my right foot on top of my toes started with big toe now its moving to rest of my toes and climbing up towards top of my right foot also got it started under my little toe. Its dark brown hard scales. Toes don't hurt but under my foot does where its new. Like big calus.tips of my toes red.what might it be looked on web MD I am stumped.