CrazyTalk Animator lets you modify the inner mouth and throat color for when mouths need to be opened wide.
After you apply a virtual mouth, you may then modify the oral color.

Changing Throat Color
  1. Click the Teeth Setting button at the tool bar to access the Teeth Settings panel.
  2. Choose the Throat radio button.
  3. In the Color section, adjust the value of the Brightness, Contrast, Hue and Saturation.

    Narrow throat

    Deep throat