diff --git a/app/src/main/java/eu/faircode/email/EntityRule.java b/app/src/main/java/eu/faircode/email/EntityRule.java
index 267d0c7a32..751c5d34e4 100644
--- a/app/src/main/java/eu/faircode/email/EntityRule.java
+++ b/app/src/main/java/eu/faircode/email/EntityRule.java
@@ -83,6 +83,7 @@ public class EntityRule {
     static final int TYPE_MOVE = 3;
     static final int TYPE_ANSWER = 4;
     static final int TYPE_AUTOMATION = 5;
+    static final int TYPE_FLAG = 6;
 
     static final String ACTION_AUTOMATION = BuildConfig.APPLICATION_ID + ".AUTOMATION";
     static final String EXTRA_RULE = "rule";
@@ -206,6 +207,9 @@ public class EntityRule {
                 case TYPE_UNSEEN:
                     onActionSeen(context, db, message, false);
                     break;
+                case TYPE_FLAG:
+                    onActionFlag(context, db, message, jaction);
+                    break;
                 case TYPE_MOVE:
                     onActionMove(context, db, message, jaction);
                     break;
@@ -293,6 +297,12 @@ public class EntityRule {
         }
     }
 
+    private void onActionFlag(Context context, DB db, EntityMessage message, JSONObject jargs) throws JSONException {
+        Integer color = (jargs.has("color") && !jargs.isNull("color")
+                ? jargs.getInt("color") : null);
+        EntityOperation.queue(context, db, message, EntityOperation.FLAG, true, color);
+    }
+
     @Override
     public boolean equals(Object obj) {
         if (obj instanceof EntityRule) {
diff --git a/app/src/main/java/eu/faircode/email/FragmentRule.java b/app/src/main/java/eu/faircode/email/FragmentRule.java
index 6f762f409c..cff8e2cdc8 100644
--- a/app/src/main/java/eu/faircode/email/FragmentRule.java
+++ b/app/src/main/java/eu/faircode/email/FragmentRule.java
@@ -23,6 +23,8 @@ import android.content.Context;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.database.Cursor;
+import android.graphics.Color;
+import android.graphics.drawable.GradientDrawable;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.Handler;
@@ -34,6 +36,7 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.widget.AdapterView;
 import android.widget.ArrayAdapter;
+import android.widget.Button;
 import android.widget.CheckBox;
 import android.widget.EditText;
 import android.widget.ImageView;
@@ -47,6 +50,8 @@ import androidx.constraintlayout.widget.ConstraintLayout;
 import androidx.constraintlayout.widget.Group;
 import androidx.fragment.app.FragmentTransaction;
 
+import com.android.colorpicker.ColorPickerDialog;
+import com.android.colorpicker.ColorPickerSwatch;
 import com.google.android.material.bottomnavigation.BottomNavigationView;
 import com.google.android.material.snackbar.Snackbar;
 
@@ -86,16 +91,25 @@ public class FragmentRule extends FragmentBase {
 
     private Spinner spAction;
     private TextView tvActionRemark;
+
+    private Button btnColor;
+    private View vwColor;
+    private ImageView ibColorDefault;
+
     private Spinner spTarget;
+
     private Spinner spIdent;
+
     private Spinner spAnswer;
     private CheckBox cbCc;
+
     private TextView tvAutomation;
 
     private BottomNavigationView bottom_navigation;
     private ContentLoadingProgressBar pbWait;
 
     private Group grpReady;
+    private Group grpFlag;
     private Group grpMove;
     private Group grpAnswer;
     private Group grpAutomation;
@@ -108,6 +122,7 @@ public class FragmentRule extends FragmentBase {
     private long id = -1;
     private long account = -1;
     private long folder = -1;
+    private Integer color = null;
 
     @Override
     public void onCreate(Bundle savedInstanceState) {
@@ -153,16 +168,25 @@ public class FragmentRule extends FragmentBase {
 
         spAction = view.findViewById(R.id.spAction);
         tvActionRemark = view.findViewById(R.id.tvActionRemark);
+
+        btnColor = view.findViewById(R.id.btnColor);
+        vwColor = view.findViewById(R.id.vwColor);
+        ibColorDefault = view.findViewById(R.id.ibColorDefault);
+
         spTarget = view.findViewById(R.id.spTarget);
+
         spIdent = view.findViewById(R.id.spIdent);
+
         spAnswer = view.findViewById(R.id.spAnswer);
         cbCc = view.findViewById(R.id.cbCc);
+
         tvAutomation = view.findViewById(R.id.tvAutomation);
 
         bottom_navigation = view.findViewById(R.id.bottom_navigation);
         pbWait = view.findViewById(R.id.pbWait);
 
         grpReady = view.findViewById(R.id.grpReady);
+        grpFlag = view.findViewById(R.id.grpFlag);
         grpMove = view.findViewById(R.id.grpMove);
         grpAnswer = view.findViewById(R.id.grpAnswer);
         grpAutomation = view.findViewById(R.id.grpAutomation);
@@ -208,6 +232,7 @@ public class FragmentRule extends FragmentBase {
         List<Action> actions = new ArrayList<>();
         actions.add(new Action(EntityRule.TYPE_SEEN, getString(R.string.title_seen)));
         actions.add(new Action(EntityRule.TYPE_UNSEEN, getString(R.string.title_unseen)));
+        actions.add(new Action(EntityRule.TYPE_FLAG, getString(R.string.title_flag)));
         actions.add(new Action(EntityRule.TYPE_MOVE, getString(R.string.title_move)));
         actions.add(new Action(EntityRule.TYPE_ANSWER, getString(R.string.title_answer_reply)));
         actions.add(new Action(EntityRule.TYPE_AUTOMATION, getString(R.string.title_rule_automation)));
@@ -243,6 +268,32 @@ public class FragmentRule extends FragmentBase {
 
         tvActionRemark.setVisibility(View.GONE);
 
+        vwColor.setBackgroundColor(color == null ? Color.TRANSPARENT : color);
+
+        btnColor.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                int color = (FragmentRule.this.color == null ? Color.TRANSPARENT : FragmentRule.this.color);
+                int[] colors = getContext().getResources().getIntArray(R.array.colorPicker);
+                ColorPickerDialog colorPickerDialog = new ColorPickerDialog();
+                colorPickerDialog.initialize(R.string.title_account_color, colors, color, 4, colors.length);
+                colorPickerDialog.setOnColorSelectedListener(new ColorPickerSwatch.OnColorSelectedListener() {
+                    @Override
+                    public void onColorSelected(int color) {
+                        setColor(color);
+                    }
+                });
+                colorPickerDialog.show(getFragmentManager(), "colorpicker");
+            }
+        });
+
+        ibColorDefault.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                setColor(null);
+            }
+        });
+
         tvAutomation.setText(getString(R.string.title_rule_automation_hint,
                 EntityRule.ACTION_AUTOMATION,
                 TextUtils.join(",", new String[]{
@@ -270,6 +321,7 @@ public class FragmentRule extends FragmentBase {
         tvFolder.setText(null);
         bottom_navigation.setVisibility(View.GONE);
         grpReady.setVisibility(View.GONE);
+        grpFlag.setVisibility(View.GONE);
         grpMove.setVisibility(View.GONE);
         grpAnswer.setVisibility(View.GONE);
         grpAutomation.setVisibility(View.GONE);
@@ -421,6 +473,10 @@ public class FragmentRule extends FragmentBase {
                     } else {
                         int type = jaction.getInt("type");
                         switch (type) {
+                            case EntityRule.TYPE_FLAG:
+                                setColor(jaction.isNull("color") ? null : jaction.getInt("color"));
+                                break;
+
                             case EntityRule.TYPE_MOVE:
                                 long target = jaction.getLong("target");
                                 for (int pos = 0; pos < adapterTarget.getCount(); pos++)
@@ -622,11 +678,24 @@ public class FragmentRule extends FragmentBase {
     }
 
     private void showActionParameters(int type) {
+        grpFlag.setVisibility(type == EntityRule.TYPE_FLAG ? View.VISIBLE : View.GONE);
         grpMove.setVisibility(type == EntityRule.TYPE_MOVE ? View.VISIBLE : View.GONE);
         grpAnswer.setVisibility(type == EntityRule.TYPE_ANSWER ? View.VISIBLE : View.GONE);
         grpAutomation.setVisibility(type == EntityRule.TYPE_AUTOMATION ? View.VISIBLE : View.GONE);
     }
 
+    private void setColor(Integer color) {
+        this.color = color;
+
+        if (color == null)
+            color = Color.TRANSPARENT;
+
+        GradientDrawable border = new GradientDrawable();
+        border.setColor(color);
+        border.setStroke(1, Helper.resolveColor(getContext(), R.attr.colorSeparator));
+        vwColor.setBackground(border);
+    }
+
     private JSONObject getCondition() throws JSONException {
         JSONObject jcondition = new JSONObject();
 
@@ -672,6 +741,10 @@ public class FragmentRule extends FragmentBase {
         if (action != null) {
             jaction.put("type", action.type);
             switch (action.type) {
+                case EntityRule.TYPE_FLAG:
+                    jaction.put("color", color);
+                    break;
+
                 case EntityRule.TYPE_MOVE:
                     EntityFolder target = (EntityFolder) spTarget.getSelectedItem();
                     jaction.put("target", target.id);
diff --git a/app/src/main/res/layout/fragment_rule.xml b/app/src/main/res/layout/fragment_rule.xml
index 0a3acd5f7d..a39bbbf657 100644
--- a/app/src/main/res/layout/fragment_rule.xml
+++ b/app/src/main/res/layout/fragment_rule.xml
@@ -369,14 +369,49 @@
                 app:layout_constraintStart_toStartOf="parent"
                 app:layout_constraintTop_toBottomOf="@id/tvActionRemark" />
 
+            <Button
+                android:id="@+id/btnColor"
+                style="@style/buttonStyleSmall"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="12dp"
+                android:minWidth="0dp"
+                android:minHeight="0dp"
+                android:tag="disable"
+                android:text="@string/title_account_color"
+                app:layout_constraintStart_toStartOf="parent"
+                app:layout_constraintTop_toBottomOf="@id/vSeparatorParameters" />
+
+            <View
+                android:id="@+id/vwColor"
+                android:layout_width="24dp"
+                android:layout_height="24dp"
+                android:layout_marginStart="12dp"
+                android:background="@color/colorAccent"
+                app:layout_constraintBottom_toBottomOf="@id/btnColor"
+                app:layout_constraintStart_toEndOf="@id/btnColor"
+                app:layout_constraintTop_toTopOf="@id/btnColor" />
+
+            <ImageView
+                android:id="@+id/ibColorDefault"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginStart="12dp"
+                android:contentDescription="@string/title_legend_default_color"
+                android:src="@drawable/baseline_delete_24"
+                app:layout_constraintBottom_toBottomOf="@id/btnColor"
+                app:layout_constraintStart_toEndOf="@id/vwColor"
+                app:layout_constraintTop_toTopOf="@id/btnColor" />
+
             <TextView
                 android:id="@+id/tvMoveTarget"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
+                android:layout_marginTop="12dp"
                 android:text="@string/title_rule_folder"
                 android:textAppearance="@style/TextAppearance.AppCompat.Small"
                 app:layout_constraintStart_toStartOf="parent"
-                app:layout_constraintTop_toBottomOf="@+id/vSeparatorParameters" />
+                app:layout_constraintTop_toBottomOf="@+id/btnColor" />
 
             <Spinner
                 android:id="@+id/spTarget"
@@ -390,6 +425,7 @@
                 android:id="@+id/tvAnswerIdentity"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
+                android:layout_marginTop="12dp"
                 android:text="@string/title_rule_identity"
                 android:textAppearance="@style/TextAppearance.AppCompat.Small"
                 app:layout_constraintStart_toStartOf="parent"
@@ -434,6 +470,7 @@
                 android:id="@+id/tvAutomation"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
+                android:layout_marginTop="12dp"
                 android:text="@string/title_rule_automation_hint"
                 android:textAppearance="@style/TextAppearance.AppCompat.Small"
                 android:textIsSelectable="true"
@@ -453,6 +490,13 @@
                 vSeparatorAction,tvAction,spAction,tvActionRemark,
                 vSeparatorParameters" />
 
+            <androidx.constraintlayout.widget.Group
+                android:id="@+id/grpFlag"
+                android:layout_width="0dp"
+                android:layout_height="0dp"
+                app:constraint_referenced_ids="
+                btnColor,vwColor,ibColorDefault" />
+
             <androidx.constraintlayout.widget.Group
                 android:id="@+id/grpMove"
                 android:layout_width="0dp"