done adding ability to change different colours in both functional core and imperative shell

functional-core/app/app-update.sml

@@ -353,6 +353,19 @@ struct
         (model, drawMsg)
       end
 
+  fun updateNum (model: app_type, inputNum) =
+    let
+      val oldNum = #num model
+      val newNum = oldNum * 10 + inputNum
+      val newNum = if newNum > 255 then 0 else newNum
+    in
+      (AppWith.num (model, newNum), [])
+    end
+
+  fun updateRed model = (AppWith.r model, [])
+  fun updateGreen model = (AppWith.g model, [])
+  fun updateBlue model = (AppWith.b model, [])
+
   fun getSaveTrianglesMsg model =
     let
       val {triangles, ...} = model
@@ -409,6 +422,10 @@ struct
         end
     | MOUSE_LEFT_RELEASE => mouseMoveOrRelease model
     | MOUSE_LEFT_CLICK => mouseLeftClick model
+    | NUM num => updateNum (model, num)
+    | KEY_R => updateRed model
+    | KEY_G => updateGreen model
+    | KEY_B => updateBlue model
     | RESIZE_WINDOW {width, height} => resizeWindow (model, width, height)
     | UNDO_ACTION => undoAction model
     | REDO_ACTION => redoAction model