diff --git a/Content.Client/Administration/UI/AdminRemarks/AdminMessagePopupWindow.xaml b/Content.Client/Administration/UI/AdminRemarks/AdminMessagePopupWindow.xaml
index eac7e37a86..311829e8b2 100644
--- a/Content.Client/Administration/UI/AdminRemarks/AdminMessagePopupWindow.xaml
+++ b/Content.Client/Administration/UI/AdminRemarks/AdminMessagePopupWindow.xaml
@@ -1,13 +1,9 @@
 <ui:FancyWindow xmlns="https://spacestation14.io"
                 xmlns:ui="clr-namespace:Content.Client.UserInterface.Controls"
-                xmlns:graphics="clr-namespace:Robust.Client.Graphics;assembly=Robust.Client"
                 VerticalExpand="True" HorizontalExpand="True"
                 Title="{Loc admin-notes-message-window-title}"
                 MinSize="600 170">
-    <PanelContainer VerticalExpand="True" HorizontalExpand="True">
-        <PanelContainer.PanelOverride>
-            <graphics:StyleBoxFlat BackgroundColor="#25252A" />
-        </PanelContainer.PanelOverride>
+    <PanelContainer VerticalExpand="True" HorizontalExpand="True" StyleClasses="BackgroundDark">
         <ScrollContainer HScrollEnabled="False" VerticalExpand="True" HorizontalExpand="True" Margin="4">
             <BoxContainer Orientation="Vertical" SeparationOverride="10" VerticalAlignment="Bottom">
                 <Label Name="AdminLabel" Text="Loading..." />
diff --git a/Content.Client/Administration/UI/AdminRemarks/AdminRemarksWindow.xaml b/Content.Client/Administration/UI/AdminRemarks/AdminRemarksWindow.xaml
index a2c4f47a22..1cc5ff786c 100644
--- a/Content.Client/Administration/UI/AdminRemarks/AdminRemarksWindow.xaml
+++ b/Content.Client/Administration/UI/AdminRemarks/AdminRemarksWindow.xaml
@@ -1,13 +1,9 @@
 <ui:FancyWindow xmlns="https://spacestation14.io"
                 xmlns:ui="clr-namespace:Content.Client.UserInterface.Controls"
-                xmlns:graphics="clr-namespace:Robust.Client.Graphics;assembly=Robust.Client"
                 VerticalExpand="True" HorizontalExpand="True"
                 Title="{Loc admin-remarks-title}"
                 SetSize="600 400">
-    <PanelContainer>
-        <PanelContainer.PanelOverride>
-            <graphics:StyleBoxFlat BackgroundColor="#25252A" />
-        </PanelContainer.PanelOverride>
+    <PanelContainer StyleClasses="BackgroundDark">
         <BoxContainer Orientation="Vertical" Margin="4">
             <ScrollContainer VerticalExpand="True" HorizontalExpand="True" HScrollEnabled="False">
                 <BoxContainer Orientation="Vertical" Name="NotesContainer" Access="Public" VerticalExpand="True" />
diff --git a/Content.Client/Administration/UI/BanList/BanListControl.xaml b/Content.Client/Administration/UI/BanList/BanListControl.xaml
index b202e92e57..b3c4803689 100644
--- a/Content.Client/Administration/UI/BanList/BanListControl.xaml
+++ b/Content.Client/Administration/UI/BanList/BanListControl.xaml
@@ -1,11 +1,7 @@
 <controls:BanListControl
     xmlns="https://spacestation14.io"
-    xmlns:controls="clr-namespace:Content.Client.Administration.UI.BanList"
-    xmlns:graphics="clr-namespace:Robust.Client.Graphics;assembly=Robust.Client">
-    <PanelContainer>
-        <PanelContainer.PanelOverride>
-            <graphics:StyleBoxFlat BackgroundColor="#25252A"/>
-        </PanelContainer.PanelOverride>
+    xmlns:controls="clr-namespace:Content.Client.Administration.UI.BanList">
+    <PanelContainer StyleClasses="BackgroundDark">
         <ScrollContainer>
             <BoxContainer Name="Bans" Access="Public" Orientation="Vertical">
                 <controls:BanListHeader Name="BansHeader"/>
diff --git a/Content.Client/Administration/UI/BanList/BanListIdsPopup.xaml b/Content.Client/Administration/UI/BanList/BanListIdsPopup.xaml
index ae8c99bc75..911986827e 100644
--- a/Content.Client/Administration/UI/BanList/BanListIdsPopup.xaml
+++ b/Content.Client/Administration/UI/BanList/BanListIdsPopup.xaml
@@ -1,9 +1,5 @@
-<Popup xmlns="https://spacestation14.io"
-       xmlns:graphics="clr-namespace:Robust.Client.Graphics;assembly=Robust.Client">
-    <PanelContainer>
-        <PanelContainer.PanelOverride>
-            <graphics:StyleBoxFlat BackgroundColor="#25252A"/>
-        </PanelContainer.PanelOverride>
+<Popup xmlns="https://spacestation14.io">
+    <PanelContainer StyleClasses="BackgroundDark">
         <BoxContainer Orientation="Vertical">
             <Label Name="ID" HorizontalExpand="True"/>
             <Label Name="IP" HorizontalExpand="True"/>
diff --git a/Content.Client/Administration/UI/Bwoink/BwoinkControl.xaml b/Content.Client/Administration/UI/Bwoink/BwoinkControl.xaml
index 89e5694b0d..05c68615eb 100644
--- a/Content.Client/Administration/UI/Bwoink/BwoinkControl.xaml
+++ b/Content.Client/Administration/UI/Bwoink/BwoinkControl.xaml
@@ -1,11 +1,7 @@
 <Control
     xmlns="https://spacestation14.io"
-    xmlns:cc="clr-namespace:Content.Client.Administration.UI.CustomControls"
-    xmlns:gfx="clr-namespace:Robust.Client.Graphics;assembly=Robust.Client">
-    <PanelContainer>
-         <PanelContainer.PanelOverride>
-            <gfx:StyleBoxFlat BackgroundColor="#25252A"/>
-         </PanelContainer.PanelOverride>
+    xmlns:cc="clr-namespace:Content.Client.Administration.UI.CustomControls">
+    <PanelContainer StyleClasses="BackgroundDark">
         <SplitContainer Orientation="Horizontal" VerticalExpand="True">
             <cc:PlayerListControl Access="Public" Name="ChannelSelector" HorizontalExpand="True" SizeFlagsStretchRatio="1" />
             <BoxContainer Orientation="Vertical" HorizontalExpand="True" SizeFlagsStretchRatio="2">
diff --git a/Content.Client/Administration/UI/Logs/AdminLogsControl.xaml b/Content.Client/Administration/UI/Logs/AdminLogsControl.xaml
index 9d3506c6ba..fc4d3ee3ac 100644
--- a/Content.Client/Administration/UI/Logs/AdminLogsControl.xaml
+++ b/Content.Client/Administration/UI/Logs/AdminLogsControl.xaml
@@ -1,10 +1,6 @@
 <Control xmlns="https://spacestation14.io"
-         xmlns:aui="clr-namespace:Content.Client.Administration.UI.CustomControls"
-         xmlns:gfx="clr-namespace:Robust.Client.Graphics;assembly=Robust.Client">
-    <PanelContainer>
-        <PanelContainer.PanelOverride>
-            <gfx:StyleBoxFlat BackgroundColor="#25252A"/>
-        </PanelContainer.PanelOverride>
+         xmlns:aui="clr-namespace:Content.Client.Administration.UI.CustomControls">
+    <PanelContainer StyleClasses="BackgroundDark">
         <BoxContainer Orientation="Horizontal">
             <BoxContainer Orientation="Vertical">
                 <BoxContainer Orientation="Horizontal" MinWidth="400">
diff --git a/Content.Client/Administration/UI/Notes/AdminNotesControl.xaml b/Content.Client/Administration/UI/Notes/AdminNotesControl.xaml
index 4ebd2d792d..326e4bf3a3 100644
--- a/Content.Client/Administration/UI/Notes/AdminNotesControl.xaml
+++ b/Content.Client/Administration/UI/Notes/AdminNotesControl.xaml
@@ -1,9 +1,5 @@
-<Control xmlns="https://spacestation14.io"
-         xmlns:gfx="clr-namespace:Robust.Client.Graphics;assembly=Robust.Client">
-    <PanelContainer>
-        <PanelContainer.PanelOverride>
-            <gfx:StyleBoxFlat BackgroundColor="#25252A"/>
-        </PanelContainer.PanelOverride>
+<Control xmlns="https://spacestation14.io">
+    <PanelContainer StyleClasses="BackgroundDark">
         <BoxContainer Orientation="Vertical">
             <ScrollContainer VerticalExpand="True" HorizontalExpand="True" HScrollEnabled="False">
                 <BoxContainer Orientation="Vertical" Name="Notes" Access="Public" VerticalExpand="True"/>
diff --git a/Content.Client/Administration/UI/Notes/AdminNotesLinePopup.xaml b/Content.Client/Administration/UI/Notes/AdminNotesLinePopup.xaml
index ba9da8eff3..f978138ca5 100644
--- a/Content.Client/Administration/UI/Notes/AdminNotesLinePopup.xaml
+++ b/Content.Client/Administration/UI/Notes/AdminNotesLinePopup.xaml
@@ -1,8 +1,8 @@
 <Popup xmlns="https://spacestation14.io"
        xmlns:gfx="clr-namespace:Robust.Client.Graphics;assembly=Robust.Client">
-    <PanelContainer>
+    <PanelContainer StyleClasses="BackgroundDark">
         <PanelContainer.PanelOverride>
-            <gfx:StyleBoxFlat BackgroundColor="#25252A" BorderThickness="1" BorderColor="#18181B"/>
+            <gfx:StyleBoxFlat BorderThickness="1" BorderColor="#18181B"/>
         </PanelContainer.PanelOverride>
         <BoxContainer Orientation="Vertical">
             <Label Name="PlayerNameLabel"/>
diff --git a/Content.Client/Cargo/UI/CargoProductRow.xaml b/Content.Client/Cargo/UI/CargoProductRow.xaml
index 29c2a6df81..b47a1e8db2 100644
--- a/Content.Client/Cargo/UI/CargoProductRow.xaml
+++ b/Content.Client/Cargo/UI/CargoProductRow.xaml
@@ -1,5 +1,4 @@
 <PanelContainer xmlns="https://spacestation14.io"
-                xmlns:gfx="clr-namespace:Robust.Client.Graphics;assembly=Robust.Client"
                 HorizontalExpand="True">
     <Button Name="MainButton"
             ToolTip=""
@@ -15,10 +14,7 @@
         <Label Name="ProductName"
                Access="Public"
                HorizontalExpand="True" />
-        <PanelContainer>
-            <PanelContainer.PanelOverride>
-                <gfx:StyleBoxFlat BackgroundColor="#25252A" />
-            </PanelContainer.PanelOverride>
+        <PanelContainer StyleClasses="BackgroundDark">
             <Label Name="PointCost"
                    Access="Public"
                    MinSize="52 32"
diff --git a/Content.Client/Silicons/Laws/Ui/LawDisplay.xaml b/Content.Client/Silicons/Laws/Ui/LawDisplay.xaml
index 427b3ff181..5a0aeab366 100644
--- a/Content.Client/Silicons/Laws/Ui/LawDisplay.xaml
+++ b/Content.Client/Silicons/Laws/Ui/LawDisplay.xaml
@@ -1,11 +1,7 @@
 <Control xmlns="https://spacestation14.io"
          xmlns:customControls="clr-namespace:Content.Client.Administration.UI.CustomControls"
-         xmlns:gfx="clr-namespace:Robust.Client.Graphics;assembly=Robust.Client"
          Margin="0 0 0 10">
-    <PanelContainer VerticalExpand="True">
-        <PanelContainer.PanelOverride>
-            <gfx:StyleBoxFlat BackgroundColor="#25252a"/>
-        </PanelContainer.PanelOverride>
+    <PanelContainer VerticalExpand="True" StyleClasses="BackgroundDark">
         <BoxContainer Orientation="Vertical"
                       HorizontalExpand="True"
                       VerticalExpand="True"
diff --git a/Content.Client/UserInterface/Systems/Chat/Widgets/ChatBox.xaml b/Content.Client/UserInterface/Systems/Chat/Widgets/ChatBox.xaml
index e242e636b3..b36fc395ef 100644
--- a/Content.Client/UserInterface/Systems/Chat/Widgets/ChatBox.xaml
+++ b/Content.Client/UserInterface/Systems/Chat/Widgets/ChatBox.xaml
@@ -1,17 +1,12 @@
 <widgets:ChatBox
     xmlns="https://spacestation14.io"
-    xmlns:graphics="clr-namespace:Robust.Client.Graphics;assembly=Robust.Client"
     xmlns:widgets="clr-namespace:Content.Client.UserInterface.Systems.Chat.Widgets"
     xmlns:controls="clr-namespace:Content.Client.UserInterface.Systems.Chat.Controls"
     MouseFilter="Stop"
     HorizontalExpand="True"
     VerticalExpand="True"
     MinSize="465 225">
-    <PanelContainer HorizontalExpand="True" VerticalExpand="True">
-        <PanelContainer.PanelOverride>
-            <graphics:StyleBoxFlat BackgroundColor="#25252AAA" />
-        </PanelContainer.PanelOverride>
-
+    <PanelContainer HorizontalExpand="True" VerticalExpand="True" StyleClasses="BackgroundDark">
         <BoxContainer Orientation="Vertical" SeparationOverride="4" HorizontalExpand="True" VerticalExpand="True">
             <OutputPanel Name="Contents" HorizontalExpand="True" VerticalExpand="True" Margin="8 8 8 4" />
             <controls:ChatInputBox HorizontalExpand="True" Name="ChatInput" Access="Public" Margin="2"/>