I was sitting at end of bed got up from end of bed to turn to grab my phone off charger and hit my ankle four days later it feels cold and numb but warm to the touch what can this mean?

Neural injury.: Sounds like you may have struck your nerve when you hit your ankle. This is not unheard of. Sensation usually returns over the course of a few days. As long as your foot has good color and works normally I wouldn't worry too much. See your doc if this is not improving.

Continue to monitor: There are many possibilities including the direct mechanical trauma, muscle sprain, ligament/tendon injury, etc. If they symptoms persist or get worse, see your physician for a full evaluation including physical examination. http://www.nlm.nih.gov/medlineplus/ankleinjuriesanddisorders.html