mobile - color card for not declared

**context**

cards from unregistered users have the wrong background color

Maquette:
<img width="306" alt="image" src="https://github.com/XPEHO/yaki_ui/assets/96787811/3e9cc597-5903-4bc6-8175-fcc8c6ad148c">

Yaki:
<img width="444" alt="image" src="https://github.com/XPEHO/yaki_ui/assets/96787811/29e89613-584a-4aa9-b926-44bf05d6f876">


**todo**
change color background