Kotlin

import android.graphics.Color
import android.os.Bundle
import android.view.WindowManager
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Set the navigation bar color to red
        window.setNavigationBarColor(Color.RED)
    }
}