How to switch between light and dark theme dynamically in app using composables

At the moment I don't have any Idea why your code not works, I'll update this answer when I find out.

but instead of using if else for colors parameter use it for the whole MaterialTheme like this and it will work:

@Composable
fun MyAppTheme(
    children: @Composable() () -> Unit
) {

    if (ThemeState.isLight) {
        MaterialTheme(colors = themeColorsLight) {
            children()
        }
    } else {
        MaterialTheme(colors = themColorDark) {
            children()
        }

    }
}

Update: seems that it's bug in Jetpack Compose dev11, I tried in dev12 and it works there.

NOTE 1: @Model has been deprecated in dev 12 change your ThemeState to

object ThemeState {
    var isLight by mutableStateOf(true)
}

more information: https://android-review.googlesource.com/c/platform/frameworks/support/+/1311293

NOTE 2 There are some problems with auto Import in recent versions of AndroidStudio If the Idea throws error: Type 'MutableState<TypeVariable(T)>' has no method 'getValue(ThemeState, KProperty<*>)' and thus it cannot serve as a delegate

Import getValue and SetValue manually.

import androidx.compose.getValue
import androidx.compose.setValue

Since 0.1.0-dev16 use these imports:

import androidx.compose.runtime.getValue
import androidx.compose.runtime.setValue