Reading from EEPROM and combining
You cannot use the + operator for that. 

However, since EEPROM.read only returns one byte and not a string, you can do a much easier implementation:

void loop()  
{ 
  char result[] = "1:2:3";
  for (int item = 0; item &lt; 3; item++)
  {
    result[item * 2] = EEPROM.read(1 + item);
  }
}


This first create a string "1:2:3", where the digits are overwritten in the for loop by that item. Note that the digits in the string do not matter, it's just some free 'comment', it also should work when using "x:x:x".