Themedd displays a “colors” panel in the customizer. This panel (and all inline styling) can be removed using the following code:

/**
 * Remove the "colors" panel from the customizer
 * Also prevents any inline styles being added to the theme.
 */
add_filter( 'themedd_customize_color_options', '__return_false' );

PHP should be added to your child theme's functions.php file.