Highlighting alternate rows in Google Spreadsheets

Alternate_row_Google_Spreadsheets.js

  function colorRowsAlternateSelection() {
  var currentSheet = SpreadsheetApp.getActiveSheet();
  var currRange = currentSheet.getActiveSelection();
  topRow = currRange.getRow();
  buttomRow = currRange.getLastRow();
  leftCol = currRange.getColumn();
  rightCol = currRange.getLastColumn();
  colorRows(topRow ,    buttomRow ,     leftCol ,    rightCol );
  }

function colorColumns( topRow , buttomRow , leftCol , rightCol )  {
  var currentSheet = SpreadsheetApp.getActiveSheet();
  for (i=leftCol; i<=rightCol; i++) {
    if ( i % 2 == 0) {
      currentSheet.getRange(topRow, i , (buttomRow-topRow)+1, 1 ).setBackgroundRGB(235, 235, 235);
    } else {
      currentSheet.getRange(topRow, i , (buttomRow-topRow)+1, 1 ).setBackgroundRGB(255, 255, 255);
    }
  }
}

That was easy : add the following function to the native code :

function colorRows( topRow , buttomRow , leftCol , rightCol ) {
var currentSheet = SpreadsheetApp.getActiveSheet();
for (i=topRow; i<=buttomRow; i++) {
if ( i % 2 == 0) {
currentSheet.getRange(i, leftCol , 1, (rightCol-leftCol+1) ).setBackgroundRGB(235, 235, 235);
} else {
currentSheet.getRange(i, leftCol , 1, (rightCol-leftCol+1) ).setBackgroundRGB(255, 255, 255);
}
}
}