Color Palette:

1. Midnight Blue
   Hex Code: 
                            
                            #191970
                        
   Description: This deep, dark blue shade represents the night sky in the city. It exudes a sense of mystery and tranquility, perfect for a cityscape-inspired card design.

2. Steel Grey
   Hex Code: 
                            
                            #808080
                        
   Description: This neutral gray color resembles the concrete structures often found in urban environments. It provides a modern and industrial touch to the palette, symbolizing the urban landscape.

3. Traffic Light Yellow
   Hex Code: 
                            
                            #FFD700
                        
   Description: Inspired by the vibrant color of traffic lights, this yellow hue adds a pop of energy and excitement to the palette. It represents the bustling streets and vibrant atmosphere of the city.

4. Metropolitan Green
   Hex Code: 
                            
                            #008080
                        
   Description: This rich green shade symbolizes the urban parks and greenery within a city. It brings a touch of nature and freshness to the palette, balancing out the other colors.

5. Cityscape Grey
   Hex Code: 
                            
                            #555555
                        
   Description: This medium gray shade represents the concrete jungle of tall buildings and skyscrapers. It conveys a sense of urban sophistication and serves as a versatile base color in the palette.

6. Taxi Cab Yellow
   Hex Code: 
                            
                            #F0C300
                        
   Description: Inspired by the iconic yellow taxis found in many cities, this bright yellow shade adds a playful and eye-catching element to the palette. It represents the dynamic and diverse nature of city life.