agingFolders.gs

function ageFolders() {
  let folder_id = '0B7Y2RaVxyfu-LU04MkxYdFhnSzg';
  let folders = DriveApp.getFolderById(folder_id).getFolders();
  var painted = [];
  while(folders.hasNext()){
    let folder = folders.next();
    let name = folder.getName();
    let date = getDateFromArt(name) || folder.getDateCreated();
    painted.push( paintFolder(folder,date) );
  }
  Logger.log(painted);
}

SpecialFolders = {
  "Video": "Bubble gum", 
  "Movies": "Purple rain", 
  "Photo": "Toy eggplant", 
  "Archive": "Rainy sky",
  "My new Documents": "Asparagus",
  "Important": "Cardinal",
  "Templates": "Chocolate ice cream",
  "Portfolio": "Denim",
  }

function paintFolder(folder,d){
  let id = folder.getId();
  let name = folder.getName();
  let age = daysTo(d);
  var color = "";
  if(name in SpecialFolders){
    color = SpecialFolders[name];
  }else{
    color = "Mouse";
    if(age<6*4*7) color = "Mountain grey";
    if(age<4*4*7) color = "Earthworm";
    if(age<2*4*7) color = "Yellow cab";
    if(age<4*7)   color = "Mars orange";
    if(age<2*7)   color = "Wild straberries";
  }
  folderColor.setColorByName(id, color);
  return {id:id, name:name, age:age, color:color};
}


var folderColor = {}

folderColor.setColorByName = function(id,name){
  if(!colorPalette[name]){
    throw "Name is not valid, please check name in colorPalette.";
  }
  this.setColor(id,colorPalette[name]);
  return true;
}

folderColor.init = function(){
  return this;
}

folderColor.setColor = function(id,hexa){
  var url = 'https://www.googleapis.com/drive/v2/files/'+id+'?fields=folderColorRgb';
  var param = {
    method      : "patch",
    contentType: 'application/json',
    headers     : {"Authorization": "Bearer " + ScriptApp.getOAuthToken()},
    payload: JSON.stringify({folderColorRgb:hexa})
  };
  var html = UrlFetchApp.fetch(url,param).getContentText();

  return html;
}

var colorPalette = {
  "Chocolate ice cream":"#ac725e",
  "Old brick red":"#d06b64",
  "Cardinal":"#f83a22",
  "Wild straberries":"#fa573c",
  "Mars orange":"#ff7537",
  "Yellow cab":"#ffad46",
  "Spearmint":"#42d692",
  "Vern fern":"#16a765",
  "Asparagus":"#7bd148",
  "Slime green":"#b3dc6c",
  "Desert sand":"#fbe983",
  "Macaroni":"#fad165",
  "Sea foam":"#92e1c0",
  "Pool":"#9fe1e7",
  "Denim":"#9fc6e7",
  "Rainy sky":"#4986e7",
  "Blue velvet":"#9a9cff",
  "Purple dino":"#b99aff",
  "Mouse":"#8f8f8f",
  "Mountain grey":"#cabdbf",
  "Earthworm":"#cca6ac",
  "Bubble gum":"#f691b2",
  "Purple rain":"#cd74e6",
  "Toy eggplant":"#a47ae2"
 };