Can the <ion-fab-list> be customized?

Hello everyone

I have implemented an <ion-fab-list> but I cannot adjust the default close button that appears when the list is open.

The default close button appearance seems to be

<button ion-fab color="primary">
<ion-icon name="close" color="light"></ion-icon>
</button>

So when i change the fab that toggles the list to
<button ion-fab color="light">
the “close” icon is not visible on the button background

Is it possible to be control color, icon, and styling either explicitly in the template or dynamically in the typescript? Unless I’ve missed something obvious, im stumped