Toan,
If you want to have Show Message text be a different color based on certain conditions, I think that will be very difficult (I just had a look at the classes used in Message popups and they are generic classes used throughout the app, so changing them will impact a lot of difference places in your app). You can solve this by creating a small popup window that you can pass text and classes into using a non persistable entity.
Hope that helps,
Mike
Hi Toan,
Please go through the below documentation,
Hope it Helps!
Thanks & Regards,
Manikandan K