How to change details of the code

As the title is a link I expect its colour is either the default for wordpress or picked up from your theme settings so you could change it there (it will change all links!).

The styling of the title is done in the following css which you can modify. I don’t know enough CSS to know if you can change the color there (see first comment above)?

.ngg-albumtitle {
    font-size: x-large;
    font-weight: normal;
    margin: 0;
    padding: 0;
    text-align: center;
}

I expect to unlink the title you’ll need to edit the code. To find out where you’ll need to scan the plugin files and look for this string <div class="ngg-thumbnail"> and below it should be the href for it.

That string will appear in several pieces of code – you want the one that matches the album shortcode you are using eg for shortcode [album id=6 template=caption] it would be file gallery-caption.php.

If you don’t already have a file content scanner you can try the one here.