You can inject custom ring color classes through injClass:
<AvatarGroup {data} injClass="!ring-white dark:!ring-gray-900" />
Use Snippet to pass custom content:
<AvatarGroup {data}>
{#snippet top()}
<div class="custom-top">Custom content</div>
{/snippet}
</AvatarGroup>
Adjust the compact parameter. Higher values mean more overlap. Default is 5, you can set values between 0-10 as needed.