What's the forecast for Neptune-like exoplanets: Cloudy or clear?

Do the Milky Way's most common planets, mini-Neptunes, have atmospheres filled with opaque clouds or a more transparent haze?

What's the forecast for Neptune-like exoplanets: Cloudy or clear?
Do the Milky Way's most common planets, mini-Neptunes, have atmospheres filled with opaque clouds or a more transparent haze?