var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Sheet1');
lastrow = sheet.getLastRow()
if (sheet.getRange(lastrow, 2, 1, 1) >0.00 && sheet.getRange(lastrow, 2, 1, 1) !='#N/A') {
  sheet.getRange(lastrow, 2, 1, 1).setFontColor('green');
}

var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Sheet1');
var oValues = sheet.getRange(2, 2, sheet.getLastRow()-1, 1).getValues();

for (var i = 0; i < oValues.length; i++) {
  if (oValues[i] >0.00) {
   sheet.getRange(i, 2, 1, 1).setFontColor('green');
  }
}