From my understanding, if you hover your mouse over a style, it will give you the style's name. Then place that style name into the section below (remove all spaces).
$paramsTable = array(
'TBLSTYLEval' => 'LightListAccent1PHPDOCX',
'jc' => 'center',
'size_col' => $widthTableCols
);
$docx->addTable($valuesTable, $paramsTable);
$docx->createDocxAndDownload('./Output/example_pie_chart');
The 'LightListAccent1PHPDOCX' should give you the 8th item there.
jc