What Micro Interaction to use When Hovering Over a Button?

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We are trying to learn/understand UX from first principals and build the most intuitive UI.
We are creating buttons in an App and want to know what the ideal micro interaction is when hovering over the button.

We have seen some tutorials decrease the Opacity of buttons when the cursor hovers over the button, however we feel this can be counterintuitive for the user as it's "greying out" the button which could mean the action is not available.

These are the buttons in the App we are currently building:

Does it make sense to reduce the opacity of the button when hovered?
What would be a more appropriate UX / micro interaction for a button?

Thanks!