So, I found a pretty nice way do that. What it does is basically slowly change the text color to a more whitish color, making as if the text is being more transparent. Here is how to do that:

colors = ['#F0F0F0', '#D3D3D3', '#BEBEBE', '#A9A9A9', '#7F7F7F', '#6A6A6A', '#545454',
          '#3F3F3F', '#2A2A2A', '#000000']  # Colors that form a gradient from VERY light grey to black
prompt.config(foreground=colors[countdown-1])

The countdown variable is the amount of second user is not typing