$('a.coollink').hover(function(){

  $(this).stop().animate({	// magic here, stop THIS object to animate
                                // and do animate from begin	
    backgroundColor: '#21545A', //animate what you want
    color: '#FFF'
  }, 500);

}, function(){

  $(this).stop().animate({	// magic here, stop THIS object to animate
                                // and do animate from begin	
    backgroundColor: '#FFF',    //animate what you want
    color: '#797979'
    }, 500);
	
});

$('a.coollink').hover(function(){

  $(this).stop().animate({	// magic here, stop THIS object to animate
                                // and do animate from begin	
    backgroundColor: '#21545A',
    color: '#FFF'
  }, 500);

}, function(){

  $(this).stop().animate({	// magic here, stop THIS object to animate
                                // and do animate from begin	
    backgroundColor: '#FFF',
    color: '#797979'
    }, 500);
	
});

$('.taxonomy a').hover(function(){

  $(this).stop().animate({	// magic here, stop THIS object to animate
                                // and do animate from begin	
    backgroundColor: '#21545A',
    color: '#FFF'
  }, 500);

}, function(){

  $(this).stop().animate({	// magic here, stop THIS object to animate
                                // and do animate from begin	
    backgroundColor: '#FFF',
    color: '#797979'
    }, 500);
	
});

For user-friendly animations on hover event. 
Prevents repeating animations when hovering object many many times.

Example needs "jquery.color" plugin for color animations. But you can use any animations you want.

Stop animations on multiple hovering

jquery, animation

JavaScript