Default swipe icon colors

app/src/main/java/eu/faircode/email/EntityFolder.java

@@ -20,6 +20,7 @@ package eu.faircode.email;
 */
 
 import android.content.Context;
+import android.graphics.Color;
 import android.text.TextUtils;
 
 import androidx.annotation.NonNull;
@@ -325,6 +326,12 @@ public class EntityFolder extends EntityOrder implements Serializable {
         return R.drawable.twotone_folder_24;
     }
 
+    static Integer getDefaultColor(String type) {
+        if (EntityFolder.TRASH.equals(type) || EntityFolder.JUNK.equals(type))
+            return Color.RED;
+        return null;
+    }
+
     String getDisplayName(Context context) {
         return (display == null ? localizeName(context, name) : display);
     }

app/src/main/java/eu/faircode/email/FragmentMessages.java

@@ -1974,7 +1974,11 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
             if (dX > 0) {
                 // Right swipe
                 d.setAlpha(Math.round(255 * Math.min(dX / (2 * margin + size), 1.0f)));
-                if (swipes.right_color != null)
+                if (swipes.right_color == null) {
+                    Integer color = EntityFolder.getDefaultColor(swipes.right_type);
+                    if (color != null)
+                        d.setTint(color);
+                } else
                     d.setTint(swipes.right_color);
                 int padding = (rect.height() - size);
                 d.setBounds(
@@ -1986,7 +1990,11 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
             } else if (dX < 0) {
                 // Left swipe
                 d.setAlpha(Math.round(255 * Math.min(-dX / (2 * margin + size), 1.0f)));
-                if (swipes.left_color != null)
+                if (swipes.left_color == null) {
+                    Integer color = EntityFolder.getDefaultColor(swipes.left_type);
+                    if (color != null)
+                        d.setTint(color);
+                } else
                     d.setTint(swipes.left_color);
                 int padding = (rect.height() - size);
                 d.setBounds(