Based on the hex code provided ( #1B1F3B ), I have generated a color palette that complements the deep, dark blue and adds some contrasting colors for a well-rounded design.

 <Deep Night>
1. Midnight Blue - 
                            
                            #1B1F3B
                         - A dark, rich blue that evokes a sense of calm and sophistication.
2. Soft Lavender - 
                            
                            #E1D5E7
                         - A light, gentle lavender that adds a touch of warmth and tranquility.
3. Silver Mist - 
                            
                            #B0B3C7
                         - A muted silver-gray that offers a modern, sleek contrast to the deep blue.
4. Coral Blush - 
                            
                            #FF6F61
                         - A vibrant coral that injects energy and brightness into the palette.
5. Misty Teal - 
                            
                            #4E8B8B
                         - A soft teal that brings in a refreshing, nature-inspired element.

This color palette, “Deep Night,” combines the serenity of dark shades with lighter, more vibrant colors to create a balanced and visually appealing scheme suitable for various design applications, such as website backgrounds, branding, or product packaging.

Would you like to explore specific applications for this color palette, or do you need variations based on different themes?