How long does it take for a tongue to turn black after death?

After death, a tongue can begin to change color due to various factors such as decomposition and the effects of bacteria. Typically, discoloration may start to occur within a few hours, and a black appearance can develop within 24 to 48 hours, depending on environmental conditions and the state of the body. Factors like temperature and humidity can also influence the rate of decomposition and discoloration.