QStyleHints::setColorScheme() doesn't affect the application's theme on Ubuntu

QStyleHints::setColorScheme() doesn't affect the application's theme on Ubuntu. The method works fine on Windows, but it doesn't seem to work on Ubuntu when trying to force the theme (dark/light) with the code below:
Qt::ColorScheme color = qApp->styleHints()->colorScheme() == Qt::ColorScheme::Light ? Qt::ColorScheme::Dark : Qt::ColorScheme::Light;
qApp->styleHints()->setColorScheme(color);