diff --git a/Signal/src/ViewControllers/ConversationView/Cells/OWSContactOffersCell.m b/Signal/src/ViewControllers/ConversationView/Cells/OWSContactOffersCell.m
index f552d7a18..10bff29a3 100644
--- a/Signal/src/ViewControllers/ConversationView/Cells/OWSContactOffersCell.m
+++ b/Signal/src/ViewControllers/ConversationView/Cells/OWSContactOffersCell.m
@@ -46,7 +46,6 @@ NS_ASSUME_NONNULL_BEGIN
     self.layoutConstraints = @[];
 
     self.titleLabel = [UILabel new];
-    self.titleLabel.textColor = [UIColor ows_light60Color];
     self.titleLabel.text = NSLocalizedString(@"CONVERSATION_VIEW_CONTACTS_OFFER_TITLE",
         @"Title for the group of buttons show for unknown contacts offering to add them to contacts, etc.");
     self.titleLabel.lineBreakMode = NSLineBreakByTruncatingTail;
@@ -98,9 +97,7 @@ NS_ASSUME_NONNULL_BEGIN
 {
     UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
     [button setTitle:title forState:UIControlStateNormal];
-    [button setTitleColor:[UIColor ows_signalBlueColor] forState:UIControlStateNormal];
     button.titleLabel.textAlignment = NSTextAlignmentCenter;
-    [button setBackgroundColor:[UIColor ows_light02Color]];
     button.layer.cornerRadius = 4.f;
     [button addTarget:self action:selector forControlEvents:UIControlEventTouchUpInside];
     return button;
@@ -118,8 +115,21 @@ NS_ASSUME_NONNULL_BEGIN
     OWSAssert(self.viewItem);
     OWSAssert([self.viewItem.interaction isKindOfClass:[OWSContactOffersInteraction class]]);
 
+    //    [OWSTableItem configureCell:self];
+    self.backgroundColor = [Theme backgroundColor];
+
     [self configureFonts];
 
+    self.titleLabel.textColor = Theme.secondaryColor;
+    for (UIButton *button in @[
+             self.addToContactsButton,
+             self.addToProfileWhitelistButton,
+             self.blockButton,
+         ]) {
+        [button setTitleColor:[UIColor ows_signalBlueColor] forState:UIControlStateNormal];
+        [button setBackgroundColor:Theme.conversationButtonBackgroundColor];
+    }
+
     OWSContactOffersInteraction *interaction = (OWSContactOffersInteraction *)self.viewItem.interaction;
 
     OWSAssert(
diff --git a/Signal/src/ViewControllers/ConversationView/Cells/OWSContactShareButtonsView.m b/Signal/src/ViewControllers/ConversationView/Cells/OWSContactShareButtonsView.m
index bd6a71808..0e3452766 100644
--- a/Signal/src/ViewControllers/ConversationView/Cells/OWSContactShareButtonsView.m
+++ b/Signal/src/ViewControllers/ConversationView/Cells/OWSContactShareButtonsView.m
@@ -113,7 +113,7 @@ NS_ASSUME_NONNULL_BEGIN
     OWSAssert([OWSContactShareButtonsView hasAnyButton:self.contactShare contactsManager:self.contactsManager]);
 
     self.layoutMargins = UIEdgeInsetsZero;
-    self.backgroundColor = [UIColor ows_light02Color];
+    self.backgroundColor = Theme.conversationButtonBackgroundColor;
 
     UILabel *label = [UILabel new];
     self.buttonView = label;
diff --git a/Signal/src/ViewControllers/ConversationView/Cells/OWSMessageBubbleView.m b/Signal/src/ViewControllers/ConversationView/Cells/OWSMessageBubbleView.m
index 9e63d8760..277eb50db 100644
--- a/Signal/src/ViewControllers/ConversationView/Cells/OWSMessageBubbleView.m
+++ b/Signal/src/ViewControllers/ConversationView/Cells/OWSMessageBubbleView.m
@@ -510,7 +510,7 @@ NS_ASSUME_NONNULL_BEGIN
 
     OWSAssert(buttonsView.backgroundColor);
     shadowView.fillColor = buttonsView.backgroundColor;
-    shadowView.layer.shadowColor = [UIColor blackColor].CGColor;
+    shadowView.layer.shadowColor = Theme.boldColor.CGColor;
     shadowView.layer.shadowOpacity = 0.12f;
     shadowView.layer.shadowOffset = CGSizeZero;
     shadowView.layer.shadowRadius = 1.f;
diff --git a/Signal/src/ViewControllers/ConversationView/Cells/OWSMessageHeaderView.m b/Signal/src/ViewControllers/ConversationView/Cells/OWSMessageHeaderView.m
index 392ce64fe..d1837ca13 100644
--- a/Signal/src/ViewControllers/ConversationView/Cells/OWSMessageHeaderView.m
+++ b/Signal/src/ViewControllers/ConversationView/Cells/OWSMessageHeaderView.m
@@ -53,12 +53,10 @@ const CGFloat OWSMessageHeaderViewDateHeaderVMargin = 23;
     [self.strokeView setContentHuggingHigh];
 
     self.titleLabel = [UILabel new];
-    self.titleLabel.textColor = [UIColor ows_light90Color];
     self.titleLabel.textAlignment = NSTextAlignmentCenter;
     self.titleLabel.lineBreakMode = NSLineBreakByTruncatingTail;
 
     self.subtitleLabel = [UILabel new];
-    self.subtitleLabel.textColor = [UIColor ows_light90Color];
     // The subtitle may wrap to a second line.
     self.subtitleLabel.numberOfLines = 0;
     self.subtitleLabel.lineBreakMode = NSLineBreakByWordWrapping;
@@ -81,6 +79,9 @@ const CGFloat OWSMessageHeaderViewDateHeaderVMargin = 23;
     OWSAssert(conversationStyle);
     OWSAssert(viewItem.unreadIndicator || viewItem.shouldShowDate);
 
+    self.titleLabel.textColor = Theme.primaryColor;
+    self.subtitleLabel.textColor = Theme.primaryColor;
+
     [self configureLabelsWithViewItem:viewItem];
 
     CGFloat strokeThickness = [self strokeThicknessWithViewItem:viewItem];
@@ -115,9 +116,9 @@ const CGFloat OWSMessageHeaderViewDateHeaderVMargin = 23;
     OWSAssert(viewItem);
 
     if (viewItem.unreadIndicator) {
-        return UIColor.ows_light60Color;
+        return (Theme.isDarkThemeEnabled ? UIColor.ows_dark60Color : UIColor.ows_light60Color);
     } else {
-        return UIColor.ows_light45Color;
+        return (Theme.isDarkThemeEnabled ? UIColor.ows_dark30Color : UIColor.ows_light45Color);
     }
 }
 
diff --git a/Signal/src/ViewControllers/ConversationView/Cells/OWSSystemMessageCell.m b/Signal/src/ViewControllers/ConversationView/Cells/OWSSystemMessageCell.m
index 6c51b30d8..cb79b795c 100644
--- a/Signal/src/ViewControllers/ConversationView/Cells/OWSSystemMessageCell.m
+++ b/Signal/src/ViewControllers/ConversationView/Cells/OWSSystemMessageCell.m
@@ -76,7 +76,6 @@ typedef void (^SystemMessageActionBlock)(void);
 
     self.layoutMargins = UIEdgeInsetsZero;
     self.contentView.layoutMargins = UIEdgeInsetsZero;
-    self.contentView.backgroundColor = UIColor.whiteColor;
     self.layoutConstraints = @[];
 
     self.headerView = [OWSMessageHeaderView new];
@@ -103,7 +102,6 @@ typedef void (^SystemMessageActionBlock)(void);
     self.button = [UIButton buttonWithType:UIButtonTypeCustom];
     [self.button setTitleColor:[UIColor ows_darkSkyBlueColor] forState:UIControlStateNormal];
     self.button.titleLabel.textAlignment = NSTextAlignmentCenter;
-    [self.button setBackgroundColor:[UIColor ows_light02Color]];
     self.button.layer.cornerRadius = 4.f;
     [self.button addTarget:self action:@selector(buttonWasPressed:) forControlEvents:UIControlEventTouchUpInside];
     [self.button autoSetDimension:ALDimensionHeight toSize:self.buttonHeight];
@@ -164,6 +162,8 @@ typedef void (^SystemMessageActionBlock)(void);
     OWSAssert(self.viewItem);
     OWSAssert(transaction);
 
+    [self.button setBackgroundColor:Theme.conversationButtonBackgroundColor];
+
     TSInteraction *interaction = self.viewItem.interaction;
 
     self.action = [self actionForInteraction:interaction];
@@ -219,14 +219,14 @@ typedef void (^SystemMessageActionBlock)(void);
 
 - (UIColor *)textColor
 {
-    return [UIColor ows_light60Color];
+    return Theme.secondaryColor;
 }
 
 - (UIColor *)iconColorForInteraction:(TSInteraction *)interaction
 {
     // "Phone", "Shield" and "Hourglass" icons have a lot of "ink" so they
     // are less dark for balance.
-    return [UIColor ows_light60Color];
+    return Theme.secondaryColor;
 }
 
 - (nullable UIImage *)iconForInteraction:(TSInteraction *)interaction
diff --git a/Signal/src/ViewControllers/ConversationView/ConversationViewController.m b/Signal/src/ViewControllers/ConversationView/ConversationViewController.m
index 5c5f4b3b5..95190f62b 100644
--- a/Signal/src/ViewControllers/ConversationView/ConversationViewController.m
+++ b/Signal/src/ViewControllers/ConversationView/ConversationViewController.m
@@ -234,6 +234,7 @@ typedef enum : NSUInteger {
 @property (nonatomic) ContactShareViewHelper *contactShareViewHelper;
 @property (nonatomic) NSTimer *reloadTimer;
 @property (nonatomic, nullable) NSDate *lastReloadDate;
+@property (nonatomic) BOOL didChangeTheme;
 
 @end
 
@@ -352,6 +353,10 @@ typedef enum : NSUInteger {
                                              selector:@selector(keyboardWillChangeFrame:)
                                                  name:UIKeyboardWillChangeFrameNotification
                                                object:nil];
+    [[NSNotificationCenter defaultCenter] addObserver:self
+                                             selector:@selector(themeDidChange:)
+                                                 name:ThemeDidChangeNotification
+                                               object:nil];
 }
 
 - (BOOL)isGroupConversation
@@ -560,14 +565,7 @@ typedef enum : NSUInteger {
 
     [self addNotificationListeners];
     [self loadDraftInCompose];
-}
-
-- (void)loadView
-{
-    [super loadView];
-
-    // make sure toolbar extends below iPhoneX home button.
-    self.view.backgroundColor = Theme.toolbarBackgroundColor;
+    [self applyTheme];
 }
 
 - (void)createContents
@@ -589,7 +587,6 @@ typedef enum : NSUInteger {
     self.collectionView.showsVerticalScrollIndicator = YES;
     self.collectionView.showsHorizontalScrollIndicator = NO;
     self.collectionView.keyboardDismissMode = UIScrollViewKeyboardDismissModeInteractive;
-    self.collectionView.backgroundColor = [UIColor whiteColor];
     [self.view addSubview:self.collectionView];
     [self.collectionView autoPinEdgesToSuperviewEdges];
 
@@ -1188,6 +1185,13 @@ typedef enum : NSUInteger {
             [self becomeFirstResponder];
         }
     }
+
+    if (self.didChangeTheme) {
+        self.didChangeTheme = NO;
+
+        [self applyTheme];
+        [self.collectionView reloadData];
+    }
 }
 
 // `viewWillDisappear` is called whenever the view *starts* to disappear,
@@ -4243,6 +4247,26 @@ typedef enum : NSUInteger {
     }
 }
 
+- (void)themeDidChange:(NSNotification *)notification
+{
+    OWSAssertIsOnMainThread();
+
+    [self applyTheme];
+    [self.collectionView reloadData];
+    self.didChangeTheme = YES;
+}
+
+- (void)applyTheme
+{
+    OWSAssertIsOnMainThread();
+
+    // make sure toolbar extends below iPhoneX home button.
+    self.view.backgroundColor = Theme.toolbarBackgroundColor;
+    self.collectionView.backgroundColor = Theme.backgroundColor;
+
+    [self updateNavigationBarSubtitleLabel];
+}
+
 - (void)attachmentApproval:(AttachmentApprovalViewController *)attachmentApproval didApproveAttachment:(SignalAttachment * _Nonnull)attachment
 {
     [self sendMessageAttachment:attachment];
diff --git a/SignalMessaging/categories/Theme.h b/SignalMessaging/categories/Theme.h
index 2a5cc56e6..ca0e76eae 100644
--- a/SignalMessaging/categories/Theme.h
+++ b/SignalMessaging/categories/Theme.h
@@ -34,7 +34,9 @@ extern NSString *const ThemeDidChangeNotification;
 
 @property (class, readonly, nonatomic) UIColor *toolbarBackgroundColor;
 
-+ (UIColor *)cellSelectedColor;
+@property (class, readonly, nonatomic) UIColor *conversationButtonBackgroundColor;
+
+@property (class, readonly, nonatomic) UIColor *cellSelectedColor;
 
 #pragma mark -
 
diff --git a/SignalMessaging/categories/Theme.m b/SignalMessaging/categories/Theme.m
index b6ff7256e..551fec985 100644
--- a/SignalMessaging/categories/Theme.m
+++ b/SignalMessaging/categories/Theme.m
@@ -96,6 +96,11 @@ NSString *const ThemeKeyThemeEnabled = @"ThemeKeyThemeEnabled";
     return (Theme.isDarkThemeEnabled ? UIColor.ows_whiteColor : UIColor.ows_blackColor);
 }
 
++ (UIColor *)conversationButtonBackgroundColor
+{
+    return (Theme.isDarkThemeEnabled ? UIColor.ows_dark05Color : UIColor.ows_light02Color);
+}
+
 #pragma mark -
 
 + (UIBarStyle)barStyle
@@ -106,6 +111,7 @@ NSString *const ThemeKeyThemeEnabled = @"ThemeKeyThemeEnabled";
         return UIBarStyleDefault;
     }
 }
+
 @end
 
 NS_ASSUME_NONNULL_END