gui: make the drawings slightly off-white

Some randome color off the google colour picker that's supposed to look more
like a real paper color. This also means we set the general background white
now to give it a better contrast.

tuhi-gui.in

@@ -26,6 +26,9 @@ def gtk_style():
     .bg-white {
       background-color: white;
     }
+    .bg-paper {
+      background-color: #ebe9e8;
+    }
     .drawing {
       border: 2px outset #0d0d0d;
       background-color: #c4dbff;

tuhigui/data/ui/Drawing.ui

@@ -139,7 +139,7 @@
         <property name="can_focus">False</property>
         <property name="stock">gtk-missing-image</property>
         <style>
-          <class name="bg-white"/>
+          <class name="bg-paper"/>
         </style>
       </object>
       <packing>

tuhigui/data/ui/DrawingPerspective.ui

@@ -29,6 +29,9 @@
                         <property name="visible">True</property>
                         <property name="can_focus">False</property>
                         <property name="orientation">vertical</property>
+                        <style>
+                          <class name="bg-white"/>
+                        </style>
                       </object>
                     </child>
                   </object>