You can stencil it! https://www.hometalk.com/43309569/tips-tricks-you-must-know-to-stencil-walls-like-a-pro
Native is right, you can stencil. Or depending on your taste and decor, washi tape will work.
Margo: I think you're really smart! Wallpaper is terrible to remove when you turn of it.
here's a good source:
Yes! Here’s how we did it: https://www.frugalfamilytimes.com/2017/11/metallic-gold-soft-green-wall-diy-paint.html?m=1