Are the new images the same size as the old ones? If not you will have to make changes to the CSS to match the new images size. Often they are just a pixel or two of.
To change the link color you need to add a class declaration in the anchor tag.
<a href="product.php?productid={$products[product].productid}&cat={$cat}&page={$navigation_p age}{if $featured eq 'Y'}&featured{/if}"
class="white">
Then make a new class.
A.white:link {
COLOR: #ffffff;
TEXT-DECORATION: none;
display:block
}
A.white:visited {
COLOR: #ffffff;
TEXT-DECORATION: none;
display:block
}
A.white:hover {
COLOR: #ffffff;
TEXT-DECORATION: none;
display:block
}
A.white:active {
COLOR: #ffffff;
TEXT-DECORATION: none;
display:block
}