change color of the cell in excel by formula code example

Example: excel sheet cell color formula

//create this function on a script on sheets
function GetCellColorCode(input) 
{ 
  var ss = SpreadsheetApp.getActiveSpreadsheet(); 
  var cell = ss.getRange(input); 
  var result = cell.getBackground(); 
  return result 
}

...

// then use this code inside cell
=GetCellColorCode("A"&ROW())

...

// result will be the color in hex
> #fffff