Google Spreadsheet setBackgroundColors() "Deprecated" - google-apps-script

Question

A gs I have been using in the past to check for duplicates, is no longer working. The script would check all cells in the spread sheet if any were identical it would highlight all their occurrences green. I also had another function that would revert all the cells back to white.
setBackgroundColors() has been deprecated; people have been recommended to now use setBackground(). The script still doesn't work...
Here is my gs, make a copy and fiddle with it. Many Thanks...
https://docs.google.com/spreadsheets/d/1UELTxZRZPKQKU9NsQwNefvdxJDM0xDt8904sZy3etoY/edit#gid=0
Here is the script.
/**
* Retrieves all the rows in the active spreadsheet that contain data and logs the
* values for each row.
* For more information on using the Spreadsheet API, see
* https://developers.google.com/apps-script/service_spreadsheet
*/
function readRows() {
var sheet = SpreadsheetApp.getActiveSheet();
var rows = sheet.getDataRange();
var numRows = rows.getNumRows();
var values = rows.getValues();
for (var i = 0; i <= numRows - 1; i++) {
var row = values[i];
Logger.log(row);
}
};
/**
* Adds a custom menu to the active spreadsheet, containing a single menu item
* for invoking the readRows() function specified above.
* The onOpen() function, when defined, is automatically invoked whenever the
* spreadsheet is opened.
* For more information on using the Spreadsheet API, see
* https://developers.google.com/apps-script/service_spreadsheet
*/
function onOpen() {
var spreadsheet = SpreadsheetApp.getActiveSpreadsheet();
var entries = [{
name : "Check Directory",
functionName : "CheckDirectory"
}];
spreadsheet.addMenu("Script Center Menu", entries);
};
function CheckDirectory() {
var sheet = SpreadsheetApp.getActiveSheet();
var dataRange = sheet.getDataRange();
var data = dataRange.getValues();
var numRows = data.length;
var numColumns = data[0].length;
var formats = [];
var values = [];
for (var i = 0; i < numRows; i++) {
formats[i] = [];
for (var j = 0; j < numColumns; j++) {
formats[i][j] = 'white';
if (data[i][j] != '') {
values.push([data[i][j], i, j]);
}
}
}
var numValues = values.length;
for (var k = 0 ; k < numValues - 1; k++) {
if (formats[values[k][1]][values[k][2]] == 'white') {
for (var l = k + 1; l < numValues; l++) {
if (values[k][0] == values[l][0]) {
formats[values[k][1]][values[k][2]] = 'green';
formats[values[l][1]][values[l][2]] = 'green';
}
}
}
}
dataRange.setBackground(formats);
};
function resetCheckDirectory() {
var sheet = SpreadsheetApp.getActiveSheet();
var dataRange = sheet.getDataRange();
var data = dataRange.getValues();
var numRows = data.length;
var numColumns = data[0].length;
var formats = [];
var values = [];
for (var i = 0; i < numRows; i++) {
formats[i] = [];
for (var j = 0; j < numColumns; j++) {
formats[i][j] = 'white';
if (data[i][j] != '') {
values.push([data[i][j], i, j]);
}
}
}
var numValues = values.length;
for (var k = 0 ; k < numValues - 1; k++) {
if (formats[values[k][1]][values[k][2]] == 'white') {
for (var l = k + 1; l < numValues; l++) {
if (values[k][0] == values[l][0]) {
formats[values[k][1]][values[k][2]] = 'white';
formats[values[l][1]][values[l][2]] = 'white';
}
}
}
}
dataRange.setBackground(formats);
};

Answer 1

Use setBackgrounds(). With an s since it's a method that applies multiple background colors to multiple cells