How to override the entire parent theme functions.php with the child-theme

Hello!
Is there a way to not use any of the parent-theme’s functions but only use the functions declared in child theme’s functions.php?

Also, how could I override a spesific function from parent theme’s functions.php? For example I have this piece of code in my parent theme’s functions.php

function et_epanel_custom_colors_css(){
	global $shortname; ?>

	<style type="text/css">
style-stuff here....

And I would like to declare in my child-theme’s functions.php not to use it.

Thank you very much for your time.