$fields->addFieldToTab(
	'Root.Main',
	new ColorPaletteField(
		'BackgroundColor',
		'Background Color',
		array(
			'White' => '#fff',
			'Black' => '#000'
		)
	)
);

$fields->addFieldToTab(
	'Root.Main',
	new GroupedColorPaletteField(
		'BackgroundColor',
		'Background Color',
		array(
			'Primary Palette' => array(
				'White' => '#fff',
				'Black' => '#000'
			),
			'Secondary Palette' => array(
				'Blue' => 'blue',
				'Red' => 'red'
			)
		)
	)
);