willzilla

Still an issue with 7.3.0. The link mariasangria provided holds the solution for the fix within the page’s documentation. To summarize the fix:

• Go to Appearance > Theme File Editor.
• Click on functions.php under Theme Files.
• Scroll to bottom of the file and above the last line with ?> on it, paste in:

add_filter( 'wcpay_upe_appearance', function ( $appearance ) {
	unset( $appearance->rules->{'.Input'} );
	$appearance->rules->{'.Input'} = [
		'colorText' => 'white',
	];

	return $appearance;
} );

• Click Update File to save.
• Change to a different theme and then change back to clear transients.

Your credit card fields should no longer be the unreadable black and now good to go.