The rules you added near the middle of stylesheet_categories_dressing.css were not specific enough to overcome the existing rules at the bottom of the file:
Code:
/* top category hover effects*/
#categories li.cat-top a:hover {
    color: #ff9933; 
    background:  #ddeeff url(../images/catbghover.gif);
    } 

/* subcategory hover effects*/
#categories li li.cat-subs a:hover, #categories li li.cat-products a:hover {
    color: #aa9966; 
    background: #ffb9ff url(../images/catbghover.gif);
    }
Change those color and background properties as you like, and delete the color from these rules:
Code:
li.cat-top a {text-decoration:none;
color: black;
}
li.cat-top a:hover {
color: black;
background:#FFCC66;

}