Did you notice, also, how the nationality always comes right before the noun? So, the order here would be: adjective, color adjective, nationality, noun.
Example: The old blue book. Or, a black French bulldog.
Of course, don’t worry if you mix some of these up, people will still undersand you, and the point is to be understood. The main thing to remember, really, is to keep nationalities right next to the noun. Example: a tall Polish man.
Now it’s your turn to try. Look around you and write a paragraph describing what you see. That could mean: describing the room you are in, the view from your window, or the person sitting next to you at the office. The best way to improve is to practice a specific skill until you get it right. So if that skill is descriptive writing, then you must describe things as well as you can, then go back and edit. Ask someone who has already mastered the skill to give you feedback, then edit again, etc.
Good luck. If you have any questions, let me know, I’m here to help!