Android 8.1: cannot use custom LED notification color

Question

I am trying to use custom LED color (e.g. using Color.RED) for notification. I am calling class function UtilsMinimal.showNotification(...) providing context from BroadcastReceiver.

I am using the new NotificationChannel API (yes, I tried the deprecated one too including notification.defaults = 0 and 'notification.argb = ...`). Whatever I try, when I run program, the LED is pink (I don't event dream to make it blink). No other program is using LED.

What should I do? Messenger, Skype, Viber and other apps do use blue, pink and green color for LED notifications successfully.

...

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.content.Context;
import android.media.AudioAttributes;
import android.os.Build;
import android.provider.Settings;

public class UtilsMinimal {
    private static final String DEFAULT_ID = "default";

    // https://www.programcreek.com/java-api-examples/?code=rongcloud%2Fsealrtc-android%2Fsealrtc-android-master%2Fapp%2Fsrc%2Fmain%2Fjava%2Fcn%2Frongcloud%2Frtc%2Fupdateapk%2FUpdateService.java
    private static Notification.Builder createNotification(
            Context context, String title, String content, Integer progressPercent) {
        boolean isLollipop = (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP);
        int smallIcon =
                context.getResources()
                        .getIdentifier(
                                "notification_small_icon", "drawable", context.getPackageName());

        if (smallIcon <= 0 || !isLollipop) {
            smallIcon = context.getApplicationInfo().icon;
        }

        Notification.Builder builder = new Notification.Builder(context, DEFAULT_ID);
        builder.setSmallIcon(smallIcon);
        builder.setCategory(Notification.CATEGORY_ALARM);

        if (progressPercent != null) {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                builder.setCategory(Notification.CATEGORY_PROGRESS);
            }
            builder.setProgress(100, progressPercent, false);
        }

        builder.setContentTitle(title);
        if (content != null)
            builder.setContentText(content);
        builder.setAutoCancel(false);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            builder.setChannelId(DEFAULT_ID);
        }

        return builder;
    }

    static void showNotification(
            String title,
            String content,
            Context ctx,
            boolean vibrate,
            int ledColor) {
        NotificationManager mNotificationManager = (NotificationManager) ctx.getSystemService(Context.NOTIFICATION_SERVICE);
        Notification.Builder mBuilder = createNotification(ctx, title, content, null);

        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            NotificationChannel channel = new NotificationChannel(
                    DEFAULT_ID,
                    "NOTIF_CHANNEL",
                    NotificationManager.IMPORTANCE_DEFAULT);
            channel.setDescription("CHANNEL FOR INFORMING ABOUT MESSAGE RECEIVED");
            channel.enableLights(true);
            channel.setLightColor(ledColor);
            channel.shouldShowLights();
            if (vibrate) {
                long[] vibrationPattern = new long[]{300, 300, 600, 600, 500, 100};
                channel.setVibrationPattern(vibrationPattern);
                channel.enableVibration(true);
            }
            AudioAttributes att = new AudioAttributes.Builder()
                    .setUsage(AudioAttributes.USAGE_NOTIFICATION)
                    .setContentType(AudioAttributes.CONTENT_TYPE_SPEECH)
                    .build();
            channel.setSound(Settings.System.DEFAULT_NOTIFICATION_URI, att);
            mNotificationManager.createNotificationChannel(channel);
            mBuilder.setChannelId(DEFAULT_ID);
        }
        Notification notification = mBuilder.build();
//        notification.defaults = 0;
//        notification.ledARGB = ledColor;
        mNotificationManager.notify(0, notification);
    }
}