Is it possible to edit the "Non-Working Time Warning"-message to make it more visible

Hi,

Our customer asked us to increase the visibility of the warning message when you try to set the schedule of an active technician to non-working time. There is only the light grey text at the bottom with the warning. They wish to make this red or open the warning in a pop-up.

Is there any possibility to change this behaviour on our side? I only know about changing the text.

Thanks and br,
David