function setColors(uint8 x, uint8 y, bytes32[chunk_size] clr) external payable
    withinBounds(x,y)
    hasTheMoneys(x,y)
  {
    Chunk storage p = screen[getIndex(x,y)];
    
    uint refund = p.value;
    address oldOwner = p.owner;
    
    p.value = msg.value;
    p.owner = msg.sender;
    p.colors = clr;
    
    touch(x,y);

    oldOwner.send(refund); 
  }