Hi,
I’m not sure about sizing, but you can change the border in the css style sheet box in the gallery tab under style section. Look for the section that says
/* ———– Album Styles Extend ————-*/
and change the relevant image type. For thumbnails that is the following section:
.ngg-thumbnail img {
background-color:#[add hex number for your colour choice here];/*default is #ffffff */
border:1px solid #[add hex number for your colour choice here];/*default is #A9A9A9 */
margin:4px 0px 4px 5px;
padding:4px;
position:relative;
}
.ngg-album {
/*height: 130px;*/
padding: 5px;
margin-bottom: 5px;
border: 1px solid #[add hex number for your colour choice here];/*default is #cccccc – is the border around album*/
overflow:hidden;
}