Hi Jakub,
Thank you for using syncfusion product.
As per the current implementation of Gridcontrol, we can change the appearance of gridcontrol alone. we have provided a UG document to set the gridcontrol appearance please refer following link. we regret to let you know that the Gridcontrol PrintDialogue does not have any direct or extensibility support to change the color or style. Please get back to us for any further assistance.
Thanks & Regards,
Balamurugan Thirumalaikumar