Google App macro script for coloring cells that are selected disjointly in Google Sheets

color_google_sheet_cells.gs

function colorSelectedRangeGreen() {
  var sel = SpreadsheetApp.getActive().getSelection().getActiveRangeList().getRanges();
  for(var i = 0; i < sel.length; i++){
    var cell = sel[i].setBackground("#93c47d");
  }
}

function colorSelectedRangePink() {
  var sel = SpreadsheetApp.getActive().getSelection().getActiveRangeList().getRanges();
  for(var i = 0; i < sel.length; i++){
    var cell = sel[i].setBackground("#ffcccc");
  }
}

function colorSelectedRangeBlue() {
  var sel = SpreadsheetApp.getActive().getSelection().getActiveRangeList().getRanges();
  for(var i = 0; i < sel.length; i++){
    var cell = sel[i].setBackground("#b3d9ff");
  }
}

To use the macros in Google Sheets:

1. Go to Tools -> Script editor -> Paste the codes.
2. Then, go to Tools -> Macros -> Import -> Select the functions.
3. Can optionally assign shortcut keys by Tools -> Macros -> Manage macros.