diff --git a/emacs/notmuch-crypto.el b/emacs/notmuch-crypto.el
index e376aa80..68a7e9f3 100644
--- a/emacs/notmuch-crypto.el
+++ b/emacs/notmuch-crypto.el
@@ -42,7 +42,12 @@ mode."
   :group 'notmuch-crypto)
 
 (defface notmuch-crypto-part-header
-  '((t (:foreground "blue")))
+  '((((class color)
+      (background dark))
+     (:foreground "LightBlue1"))
+    (((class color)
+      (background light))
+     (:foreground "blue")))
   "Face used for crypto parts headers."
   :group 'notmuch-crypto
   :group 'notmuch-faces)
diff --git a/emacs/notmuch-tag.el b/emacs/notmuch-tag.el
index 1b2ce5c2..09d182df 100644
--- a/emacs/notmuch-tag.el
+++ b/emacs/notmuch-tag.el
@@ -115,7 +115,12 @@ Used in the default value of `notmuch-tag-formats`."
   :group 'notmuch-faces)
 
 (defface notmuch-tag-flagged
-  '((t :foreground "blue"))
+  '((((class color)
+      (background dark))
+     (:foreground "LightBlue1"))
+    (((class color)
+      (background light))
+     (:foreground "blue")))
   "Face used for the flagged tag.
 
 Used in the default value of `notmuch-tag-formats`."
diff --git a/emacs/notmuch.el b/emacs/notmuch.el
index ef4bb2b1..44519b7a 100644
--- a/emacs/notmuch.el
+++ b/emacs/notmuch.el
@@ -313,7 +313,11 @@ there will be called at other points of notmuch execution."
   :group 'notmuch-faces)
 
 (defface notmuch-search-flagged-face
-  '((t
+  '((((class color)
+      (background dark))
+     (:foreground "LightBlue1"))
+    (((class color)
+      (background light))
      (:foreground "blue")))
   "Face used in search mode face for flagged threads.