Index: ps/trunk/source/gui/CGUI.h
===================================================================
--- ps/trunk/source/gui/CGUI.h
+++ ps/trunk/source/gui/CGUI.h
@@ -138,6 +138,12 @@
 	void UnsetObjectHotkey(IGUIObject* pObject, const CStr& hotkeyTag);
 
 	/**
+	 * Allows the JS side to modify the style setting assigned to a GUI object.
+	 */
+	void SetObjectStyle(IGUIObject* pObject, const CStr& styleName);
+	void UnsetObjectStyle(IGUIObject* pObject);
+
+	/**
 	 * Allows the JS side to add or remove global hotkeys.
 	 */
 	void SetGlobalHotkey(const CStr& hotkeyTag, const CStr& eventName, JS::HandleValue function);
Index: ps/trunk/source/gui/CGUI.cpp
===================================================================
--- ps/trunk/source/gui/CGUI.cpp
+++ ps/trunk/source/gui/CGUI.cpp
@@ -389,6 +389,19 @@
 	}
 }
 
+void CGUI::SetObjectStyle(IGUIObject* pObject, const CStr& styleName)
+{
+	// If the style is not recognised (or an empty string) then ApplyStyle will
+	// emit an error message. Thus we don't need to handle it here.
+	if (pObject->ApplyStyle(styleName))
+		pObject->m_Style = styleName;
+}
+
+void CGUI::UnsetObjectStyle(IGUIObject* pObject)
+{
+	SetObjectStyle(pObject, "default");
+}
+
 void CGUI::SetObjectHotkey(IGUIObject* pObject, const CStr& hotkeyTag)
 {
 	if (!hotkeyTag.empty())
@@ -599,18 +612,11 @@
 	//
 	//	Always load default (if it's available) first!
 	//
-	CStr argStyle(attributes.GetNamedItem(attr_style));
-
-	if (m_Styles.find("default") != m_Styles.end())
-		object->LoadStyle("default");
+	SetObjectStyle(object, "default");
 
+	CStr argStyle(attributes.GetNamedItem(attr_style));
 	if (!argStyle.empty())
-	{
-		if (m_Styles.find(argStyle) == m_Styles.end())
-			LOGERROR("GUI: Trying to use style '%s' that doesn't exist.", argStyle.c_str());
-		else
-			object->LoadStyle(argStyle);
-	}
+		SetObjectStyle(object, argStyle);
 
 	bool NameSet = false;
 	bool ManuallySetZ = false;
Index: ps/trunk/source/gui/ObjectBases/IGUIObject.h
===================================================================
--- ps/trunk/source/gui/ObjectBases/IGUIObject.h
+++ ps/trunk/source/gui/ObjectBases/IGUIObject.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2019 Wildfire Games.
+/* Copyright (C) 2020 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -322,9 +322,12 @@
 	virtual InReaction ManuallyHandleKeys(const SDL_Event_* UNUSED(ev)) { return IN_PASS; }
 
 	/**
-	 * Loads a style.
+	 * Applies the given style to the object.
+	 *
+	 * Returns false if the style is not recognised (and thus has
+	 * not been applied).
 	 */
-	void LoadStyle(const CStr& StyleName);
+	bool ApplyStyle(const CStr& StyleName);
 
 	/**
 	 * Returns not the Z value, but the actual buffered Z value, i.e. if it's
Index: ps/trunk/source/gui/ObjectBases/IGUIObject.cpp
===================================================================
--- ps/trunk/source/gui/ObjectBases/IGUIObject.cpp
+++ ps/trunk/source/gui/ObjectBases/IGUIObject.cpp
@@ -162,6 +162,8 @@
 	}
 	else if (Setting == "hotkey")
 		m_pGUI.SetObjectHotkey(this, GetSetting<CStr>(Setting));
+	else if (Setting == "style")
+		m_pGUI.SetObjectStyle(this, GetSetting<CStr>(Setting));
 
 	if (SendMessage)
 	{
@@ -267,10 +269,13 @@
 	}
 }
 
-void IGUIObject::LoadStyle(const CStr& StyleName)
+bool IGUIObject::ApplyStyle(const CStr& StyleName)
 {
 	if (!m_pGUI.HasStyle(StyleName))
-		debug_warn(L"IGUIObject::LoadStyle failed");
+	{
+		LOGERROR("IGUIObject: Trying to use style '%s' that doesn't exist.", StyleName.c_str());
+		return false;
+	}
 
 	// The default style may specify settings for any GUI object.
 	// Other styles are reported if they specify a Setting that does not exist,
@@ -283,6 +288,7 @@
 		else if (StyleName != "default")
 			LOGWARNING("GUI object has no setting \"%s\", but the style \"%s\" defines it", p.first, StyleName.c_str());
 	}
+	return true;
 }
 
 float IGUIObject::GetBufferedZ() const