diff --git a/src/calibre/gui2/__init__.py b/src/calibre/gui2/__init__.py
index f1e52a7e1f..24325516d5 100644
--- a/src/calibre/gui2/__init__.py
+++ b/src/calibre/gui2/__init__.py
@@ -666,6 +666,13 @@ else:
     choose_files, choose_images, choose_dir, choose_save_file
 
 
+def is_dark_theme():
+    pal = QApplication.instance().palette()
+    col = pal.color(pal.Window)
+    h, s, v, a = col.getHsvF()
+    return v < 0.45
+
+
 def choose_osx_app(window, name, title, default_dir='/Applications'):
     fd = FileDialog(title=title, parent=window, name=name, mode=QFileDialog.ExistingFile,
             default_dir=default_dir)
diff --git a/src/calibre/gui2/book_details.py b/src/calibre/gui2/book_details.py
index 1a22001e29..6203c6fe69 100644
--- a/src/calibre/gui2/book_details.py
+++ b/src/calibre/gui2/book_details.py
@@ -8,9 +8,9 @@ from collections import namedtuple
 from functools import partial
 
 from PyQt5.Qt import (
-    QAction, QApplication, QColor, QEasingCurve, QIcon, QLayout, QMenu,
-    QMimeData, QPainter, QPen, QPixmap, QPropertyAnimation, QRect, QSize,
-    QSizePolicy, Qt, QUrl, QWidget, pyqtProperty, pyqtSignal
+    QAction, QApplication, QColor, QEasingCurve, QIcon, QLayout, QMenu, QMimeData,
+    QPainter, QPen, QPixmap, QPropertyAnimation, QRect, QSize, QSizePolicy, Qt, QUrl,
+    QWidget, pyqtProperty, pyqtSignal
 )
 
 from calibre import fit_image
@@ -23,7 +23,7 @@ from calibre.ebooks.metadata.search_internet import (
 )
 from calibre.gui2 import (
     NO_URL_FORMATTING, choose_save_file, config, default_author_link, gprefs,
-    safe_open_url, pixmap_to_data, rating_font
+    is_dark_theme, pixmap_to_data, rating_font, safe_open_url
 )
 from calibre.gui2.dnd import (
     dnd_get_files, dnd_get_image, dnd_has_extension, dnd_has_image, image_extensions
@@ -61,6 +61,13 @@ def css(reset=False):
     return css.ans
 
 
+def themed_css(reset=False):
+    ans = css(reset)
+    if is_dark_theme():
+        ans = 'a { color: #6CB4EE }\n\n' + ans
+    return ans
+
+
 def copy_all(text_browser):
     mf = getattr(text_browser, 'details', text_browser)
     c = QApplication.clipboard()
@@ -555,10 +562,10 @@ class BookInfo(HTMLDisplay):
         ac.data = (None, None, None)
         ac.triggered.connect(self.remove_item_triggered)
         self.setFocusPolicy(Qt.NoFocus)
-        self.document().setDefaultStyleSheet(css())
+        self.document().setDefaultStyleSheet(themed_css())
 
     def refresh_css(self):
-        self.document().setDefaultStyleSheet(css(True))
+        self.document().setDefaultStyleSheet(themed_css(True))
 
     def remove_item_triggered(self):
         field, value, book_id = self.remove_item_action.data
diff --git a/src/calibre/gui2/dialogs/book_info.py b/src/calibre/gui2/dialogs/book_info.py
index 118593ae0b..daadfc4cba 100644
--- a/src/calibre/gui2/dialogs/book_info.py
+++ b/src/calibre/gui2/dialogs/book_info.py
@@ -12,7 +12,7 @@ from PyQt5.Qt import (
 from calibre import fit_image
 from calibre.gui2 import NO_URL_FORMATTING, gprefs
 from calibre.gui2.book_details import (
-    css, details_context_menu_event, render_html, set_html
+    themed_css, details_context_menu_event, render_html, set_html
 )
 from calibre.gui2.ui import get_gui
 from calibre.gui2.widgets import CoverView
@@ -83,7 +83,7 @@ class Details(HTMLDisplay):
     def __init__(self, book_info, parent=None):
         HTMLDisplay.__init__(self, parent)
         self.book_info = book_info
-        self.document().setDefaultStyleSheet(css())
+        self.document().setDefaultStyleSheet(themed_css())
 
     def sizeHint(self):
         return QSize(350, 350)