<div class="testing123"><img src="images/BotGrid/images/blackFull_05_03.png"  /></div>





$(document).ready(function(){

$('.testing123').on('mouseover', function(){
    $(this).find('img').attr('src','images/BotGrid/images/yellowfull_05_03.png');
    $(this).css({"backgroundColor": "black"});
});

$('.testing123').on('mouseleave', function(){
    $(this).find('img').attr('src','images/BotGrid/images/blackfull_05_03.png');
    $(this).css({"backgroundColor": "yellow"});
});

});

<div class="bottomsquares">
<img src="images/BotGrid/images/blackFull_05_03.png"  class="static" name="aeffect" alt="" />
<img src="images/BotGrid/images/yellowfull_05_03.png"  class="rollover" name="aeffect" alt="" />

 </div>


<script>
$(document).ready(function(){
$(".rollover").hide();
$(".bottomsquares").hover(
function(){
    $(this).find(".static,.rollover").toggle();
},
function(){
    $(this).find(".static,.rollover").toggle();
});
});
</script>

<script>
$(".bottomsquares").hover(function() {

$(this).css('background-color', '#000000');
}, function() {
$(this).css('background-color', '#f9e42b');
});
</script>