abstract-block-type.js

registerBlockType( 'core/colorable', {
	abstract: true,

	attributes: {
		color: {
			type: 'string',
		},
	},

	edit: () => (
		<InspectorControls>
			<PanelColorSettings /* ... */ />
		</InspectorControls
	),

	save( { children, attributes } ) {
		const child = Children.only( children );

		return cloneElement( child, {
			style: {
				...child.props.style,
				color: attributes.color,
			},
		} );
	},
} );

registerBlockType( 'core/paragraph', {
	uses: [ 'core/colorable' ],

	// ...
} );