Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xlsx/Theme.php
public function getColourByIndex($index)
    {
        if (isset($this->colourMap[$index])) {
            return $this->colourMap[$index];
        }

        return null;
    }
public function getColourByIndex($index)
    {
        if (isset($this->colourMap[$index])) {
            return $this->colourMap[$index];
        }

        return null;
    }
Get colour Map Value by Position.

@param mixed $index

@return string