Google Apps Script to extract TextStyle information from a slide

ga_textstyle.gs

/**
 * Extract TextStyle info for the text inside slide element based on Body placeholder
 * @param {Number} slidenumber Number of the slide to analyze (starting from 1)
 */
function analyseBodyStyles(slidenumber) {
  const presentation = SlidesApp.getActivePresentation();
  const slide = presentation.getSlides()[slidenumber-1];
  const body = slide.getPlaceholders().find(ph => ph.asShape().getPlaceholderType() === SlidesApp.PlaceholderType.BODY);
  const textRange = body.asShape().getText();
  const textRuns = textRange.getRuns();
  
  textRuns.forEach((run, i) => {
    const tStyle = run.getTextStyle();

    const bgColor = tStyle.getBackgroundColor();
    const bgColorType = bgColor.getColorType();
    let colorBack = bgColorType;
    if (bgColorType == SlidesApp.ColorType.RGB) {
      colorBack = bgColor.asRgbColor().asHexString();
    } else if (bgColorType == SlidesApp.ColorType.THEME) {
      colorBack = bgColor.asThemeColor().getThemeColorType();
    }

    const fgColor = tStyle.getForegroundColor();
    const fgColorType = fgColor.getColorType();
    let colorFore = fgColorType;
    if (fgColorType == SlidesApp.ColorType.RGB) {
      colorFore = fgColor.asRgbColor().asHexString();
    } else if (fgColorType == SlidesApp.ColorType.THEME) {
      colorFore = fgColor.asThemeColor().getThemeColorType();
    }

    const isBold = (tStyle.isBold()) ? "B" : "";
    const isItalic = (tStyle.isItalic()) ? "I" : "";
    const isUnderline = (tStyle.isUnderline()) ? "U" : "";

    Logger.log(
      i + " - " 
      + run.asString().replace(/\n/g, "//") 
      + " - B: " + colorBack
      + " - F: " + colorFore
      + " [" + isBold + isItalic + isUnderline + "]"
    )
  });
}