CODE EXAMPLE FOR TYPESCRIPT

google scripts docs highlight

//Will Color the first instance of a string in a document
var document = DocumentApp.openByUrl('myURL');
var hiligherColor = '#F3E2A9';
var stringToColor = 'string';
document.getBody().findText(stringToColor).getElement().asText().setBackgroundColor(document.getBody().findText(stringToColor).getStartOffset(), document.getBody().findText(stringToColor).getEndOffsetInclusive(),(hilighterColor));