diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index 1ba8d118b76..2a41d3579e1 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -378,10 +378,6 @@ img {
 	filter: var(--rust-logo-filter);
 }
 
-.sidebar, .mobile-topbar, .sidebar-menu-toggle {
-	background-color: var(--sidebar-background-color);
-}
-
 .sidebar {
 	font-size: 0.875rem;
 	flex: 0 0 200px;
@@ -400,7 +396,8 @@ img {
 	overflow-y: hidden;
 }
 
-.source .sidebar, #src-sidebar-toggle, #source-sidebar {
+.sidebar, .mobile-topbar, .sidebar-menu-toggle,
+#src-sidebar-toggle, #source-sidebar {
 	background-color: var(--sidebar-background-color);
 }
 
diff --git a/src/test/rustdoc-gui/sidebar-source-code.goml b/src/test/rustdoc-gui/sidebar-source-code.goml
index 36e4d555b8e..d5f57ed6102 100644
--- a/src/test/rustdoc-gui/sidebar-source-code.goml
+++ b/src/test/rustdoc-gui/sidebar-source-code.goml
@@ -1,7 +1,52 @@
 // The goal of this test is to ensure that the sidebar is working as expected in the source
 // code pages.
 goto: "file://" + |DOC_PATH| + "/src/test_docs/lib.rs.html"
-// First: desktop mode.
+show-text: true
+
+// First, check the sidebar colors.
+define-function: (
+    "check-colors",
+    (theme, color, background_color),
+    [
+        ("local-storage", {
+            "rustdoc-theme": |theme|,
+            "rustdoc-use-system-theme": "false",
+        }),
+        ("reload"),
+        // Checking results colors.
+        ("assert-css", (".source .sidebar", {
+        	"color": |color|,
+        	"background-color": |background_color|
+        }, ALL)),
+    ],
+)
+
+call-function: (
+	"check-colors",
+	{
+		"theme": "ayu",
+		"color": "rgb(197, 197, 197)",
+		"background_color": "rgb(20, 25, 31)",
+	}
+)
+call-function: (
+	"check-colors",
+	{
+		"theme": "dark",
+		"color": "rgb(221, 221, 221)",
+		"background_color": "rgb(80, 80, 80)",
+	}
+)
+call-function: (
+	"check-colors",
+	{
+		"theme": "light",
+		"color": "rgb(0, 0, 0)",
+		"background_color": "rgb(245, 245, 245)",
+	}
+)
+
+// Next, desktop mode layout.
 size: (1100, 800)
 // We check that the sidebar isn't expanded and has the expected width.
 assert-css: ("nav.sidebar", {"width": "50px"})
diff --git a/src/test/rustdoc-gui/sidebar.goml b/src/test/rustdoc-gui/sidebar.goml
index 5058630f469..bfd7567a224 100644
--- a/src/test/rustdoc-gui/sidebar.goml
+++ b/src/test/rustdoc-gui/sidebar.goml
@@ -2,6 +2,50 @@
 goto: "file://" + |DOC_PATH| + "/test_docs/index.html"
 assert-property: (".sidebar", {"clientWidth": "200"})
 show-text: true
+
+// First, check the sidebar colors.
+define-function: (
+    "check-colors",
+    (theme, color, background_color),
+    [
+        ("local-storage", {
+            "rustdoc-theme": |theme|,
+            "rustdoc-use-system-theme": "false",
+        }),
+        ("reload"),
+        // Checking results colors.
+        ("assert-css", (".sidebar", {
+        	"color": |color|,
+        	"background-color": |background_color|
+        }, ALL)),
+    ],
+)
+
+call-function: (
+	"check-colors",
+	{
+		"theme": "ayu",
+		"color": "rgb(197, 197, 197)",
+		"background_color": "rgb(20, 25, 31)",
+	}
+)
+call-function: (
+	"check-colors",
+	{
+		"theme": "dark",
+		"color": "rgb(221, 221, 221)",
+		"background_color": "rgb(80, 80, 80)",
+	}
+)
+call-function: (
+	"check-colors",
+	{
+		"theme": "light",
+		"color": "rgb(0, 0, 0)",
+		"background_color": "rgb(245, 245, 245)",
+	}
+)
+
 local-storage: {"rustdoc-theme": "light"}
 // We reload the page so the local storage settings are being used.
 reload: