diff --git a/gui/colors.py b/gui/colors.py
index 1779189..44c6aeb 100644
--- a/gui/colors.py
+++ b/gui/colors.py
@@ -1,11 +1,12 @@
+# colors.py
+# Contains color definitions in the form of tuples (length 3 -> RGB representation)
+
 BLACK = (0, 0, 0)
 WHITE = (255, 255, 255)
-RED = (255, 94, 88)  # (250, 0, 0)
+RED = (255, 94, 88)
 RED_HIGHLIGHT = (255, 219, 212)
-AVAILABLE_MOVE_1 = (255, 255, 223)  # Yellow
-AVAILABLE_MOVE_2 = (255, 255, 255)  # Yellow
 GREEN = (0, 200, 0)
-BLUE = (59, 214, 255)  # (0, 0, 250)
+BLUE = (59, 214, 255)
 YELLOW = (0, 250, 250)
 
 BRIGHT_RED = (255, 0, 0)
diff --git a/gui/gui_app.py b/gui/gui_app.py
index fe674a8..01e3ff5 100644
--- a/gui/gui_app.py
+++ b/gui/gui_app.py
@@ -1,3 +1,5 @@
+from itertools import cycle, chain
+
 from gui.gui_board import *
 
 
@@ -6,32 +8,45 @@ def __init__(self):
         super(Gui, self).__init__()
         self.board = UltimateBoard()
         self.on_cell_clicked = self.subcell_clicked
+        self.allowed_cells = set()
 
     def subcell_clicked(self, x, y, w, h, board, move):
-        # todo check if the cell that is clicked is also allowed to be clicked else display warning!!!!
         # do not provide player just yet, only do so when we are sure we can click the cell
-        cell = Cell(x, y, w, h, None, board_idx=board, cell_idx=move)  # todo fix this *-1
+        cell = Cell(x, y, w, h, player=None, board_idx=board, cell_idx=move)
 
         if cell in self.clicked_cells:  # if cell already clicked -> do nothing
             return
 
+        if cell not in self.allowed_cells:
+            return  # todo raise warning or display text
+
         cell.player = self.board.playerJustMoved * -1
         self.clicked_cells.add(cell)
         self.board.make_move(move, board)
         print(board, move)
         print(self.board)
+        self.allowed_cells = self.find_allowed_cells()
+
+    def find_allowed_cells(self):
+        allowed_cells = set()  # clear currently allowed moves
 
-    def draw_allowed_moves(self, color):
         moves = self.board.get_moves()
         for board, move in moves:
             for cell in self.all_cells:
                 if cell.board_idx == board and cell.cell_idx == move:
-                    pygame.draw.rect(self.gameDisplay, color,
-                                     (cell.pos_x, cell.pos_y, cell.width, cell.height))
+                    allowed_cells.add(cell)
+
+        return allowed_cells
+
+    def draw_allowed_moves(self, color):
+        for cell in self.allowed_cells:
+            pygame.draw.rect(self.gameDisplay, color,
+                             (cell.pos_x, cell.pos_y, cell.width, cell.height))
 
     def game_loop(self):
-        highlight = AVAILABLE_MOVE_1
-        frames = 0
+        # set up an endless cycle of B values (rgB) for highlighting moves
+        highlight_range = [i for i in range(140, 201, 2)]
+        brightness_iter = cycle(chain(highlight_range, reversed(highlight_range)))
 
         while True:
             for event in pygame.event.get():
@@ -39,17 +54,20 @@ def game_loop(self):
                 if event.type == pygame.QUIT:
                     self.quit_game()
 
-            if frames == 30:
-                highlight = AVAILABLE_MOVE_1 if highlight == AVAILABLE_MOVE_2 else AVAILABLE_MOVE_2
-                frames = 0
+            brightness = next(brightness_iter)
+            highlight = (255, 255, brightness)  # yellow highlight used to accent available moves
 
             self.gameDisplay.fill(WHITE)
             self.draw_main_grid()
+
+            # todo check for game end here as well. Mind not have allowed cells because game is over
+            if not self.allowed_cells:
+                self.allowed_cells = self.find_allowed_cells()
+
             self.draw_clicked_cells()
             self.draw_allowed_moves(highlight)
             pygame.display.update()
             self.clock.tick(60)
-            frames += 1
 
 
 if __name__ == '__main__':