Great choice! A mobile app about coffee can benefit from warm and inviting colors that enhance the user experience. Here’s a refined color palette tailored for a coffee-themed app:

 < Coffee Brew> 
1. Espresso Brown - 
                            
                            #3b2a2a
                         - A deep, rich brown that resembles the color of freshly brewed espresso.
2. Creamy Beige - 
                            
                            #e6d1b3
                         - A soft, warm beige that evokes the color of steamed milk in coffee drinks.
3. Caramel Drizzle - 
                            
                            #a66b3a
                         - A warm caramel hue that adds sweetness and richness to the palette.
4. Mocha Gray - 
                            
                            #7a6e6e
                         - A muted gray with warm undertones that offers a grounding effect.
5. Coffee Cherry Red - 
                            
                            #a84b38
                         - A vibrant red that reflects the color of coffee cherries, adding a pop of color.

This “Coffee Brew” palette emphasizes the warm and inviting aspects of coffee culture, creating a cozy and enjoyable user interface for your app.

Would you like to explore font choices or visual elements that complement this color palette? Or do you need assistance with layout design ideas for the app?