Updated RGB16 palette parsing to use 16-bit RGBA strings with gdk_rgba_parse for GTK3 builds.

Parsed palette colors before initializing the GTK3 color chooser dialog to ensure RGBA normalization.
Switched GTK3 GtkCellRendererText foreground bindings to foreground-rgba with GTK2 fallbacks in user list, notify, and DCC views.

src/fe-gtk/userlistgui.c

@@ -547,9 +547,15 @@ userlist_add_columns (GtkTreeView * treeview)
 	if (prefs.hex_gui_compact)
 		g_object_set (G_OBJECT (renderer), "ypad", 0, NULL);
 	gtk_cell_renderer_text_set_fixed_height_from_font (GTK_CELL_RENDERER_TEXT (renderer), 1);
+#if GTK_CHECK_VERSION(3,0,0)
 	gtk_tree_view_insert_column_with_attributes (GTK_TREE_VIEW (treeview),
 																-1, NULL, renderer,
-													"text", 1, PALETTE_FOREGROUND_PROPERTY, 4, NULL);
+													"text", 1, "foreground-rgba", 4, NULL);
+#else
+	gtk_tree_view_insert_column_with_attributes (GTK_TREE_VIEW (treeview),
+																-1, NULL, renderer,
+													"text", 1, "foreground-gdk", 4, NULL);
+#endif
 
 	if (prefs.hex_gui_ulist_show_hosts)
 	{