<div class="item">
  item 1
</div>
<div class="item red">
  item 2
</div>
<div class="item red">
  item 3
</div>
<div class="item red">
  item 4
</div>
<div class="item">
  item 5
</div>

<div class="control">
  <input type=button id="m1" value="method 1">
  <input type=button id="m2" value="method 2">
</div>

.item {
  background: lightblue;
  float: left;
  margin: 10px;
  padding: 20px;
}

.red {
  color: red;
}

.control {
  clear: both;
}

$("#m1").click(function(){
  $("div.item").not(".red").toggle();
});

$("#m2").click(function(){
  $("div.item:not(.red)").toggle();  
});