Count the number of cells with a background color in Google Sheets (Google Apps Script)

count_colored_cells_google_apps_script.js

function CountFormattedCells() {
  
  // Output the number of formatted cells somewhere in your spreadsheet
  var outputNumberOfFormattedCells = 'C52'

  // Cell that contains the color you want to count. Default is blank.
  var cellWithFormatToCount = ''

  var spreadsheet = SpreadsheetApp.getActive();
  var currentRangeColors = spreadsheet.getActiveRange().getBackgrounds();
  if (cellWithFormatToCount !== '') { var cellWithFormat = spreadsheet.getRange(cellWithFormatToCount).getBackground(); }
  var formattedCellCount = 0
  for (var i in currentRangeColors) {
    for (var j in currentRangeColors[i]) {
      if (currentRangeColors[i][j] !== '#ffffff' && cellWithFormatToCount == '') {
        formattedCellCount++
      } else if (cellWithFormatToCount !== '' && currentRangeColors[i][j] == cellWithFormat) {
        formattedCellCount++
      }
    }
  }
  if (outputNumberOfFormattedCells != '') {
    spreadsheet.getRange(outputNumberOfFormattedCells).setValue(formattedCellCount)
  }
};