Why does the inner column not fill the whole screen? Code below results in whole screen being blue, but only a little bit red (height of the text). I would expect the inner column to fill the whole screen (and thus make the whole screen red).

Column(modifier = Modifier.fillMaxHeight().background(Color.Blue)) {
    Column(modifier = Modififer.fillMaxHeight().background(Color.Red)) {
        Text("Hi")
    }
}

Maybe you want to use Box for the outer Column?

@Timo Drick let's say the inner column has two text's above him (two siblings). Now I want the inner column to fill the remaining height. How would that happen?

just use the Modifier.weight(1f)

Thanks Timo it works. Guess it's still kind of a trap that Modifier.fillMaxHeight() exists for the column while it doesn't do anything

Modifier.fillMaxHeight()

in a

Column

definitely works. I copied your code and it's working as expected. You must have something else wrong.