code: @SuppressWarnings("SameParameterValue")
      public void setPrefix(CharSequence prefix, int color) {
          SpannableString spannablePrefix = new SpannableString(prefix);
          spannablePrefix.setSpan(new ForegroundColorSpan(color), 0, spannablePrefix.length(), 0);
          setPrefix(spannablePrefix);
      }
docs: <p>You can get a color integer either using
  {@link android.support.v4.content.ContextCompat#getColor(android.content.Context, int)}
  or with {@link android.graphics.Color#parseColor(String)}.</p>
  <p>{@link android.graphics.Color#parseColor(String)}
  accepts these formats (copied from android.graphics.Color):
  You can use: '#RRGGBB',  '#AARRGGBB'
  or one of the following names: 'red', 'blue', 'green', 'black', 'white',
  'gray', 'cyan', 'magenta', 'yellow', 'lightgray', 'darkgray', 'grey',
  'lightgrey', 'darkgrey', 'aqua', 'fuchsia', 'lime', 'maroon', 'navy',
  'olive', 'purple', 'silver', 'teal'.</p>
  
  @param prefix prefix
  @param color A single color value in the form 0xAARRGGBB.