<Shades of 4B6F8D with Rim Light and Shadows>
1. Soft Seafoam - 
                            
                            #A7C6B9
                         - A light, refreshing greenish-blue that enhances the calmness of the palette, perfect for highlights.
2. Slate Blue - 
                            
                            #4B6F8D
                         - The base color, a serene blue-gray that offers a sophisticated feel and balances the palette.
3. Muted Teal - 
                            
                            #3B5B6D
                         - A deeper blue-green shade that adds richness and depth, suitable for more complex designs.
4. Dusty Blue - 
                            
                            #5A8B9D
                         - A muted, gray-tinged blue that brings a vintage touch, harmonizing well with the base color.
5. Rim Light - 
                            
                            #B7D7E0
                         - A soft, pale blue that acts as a rim light, illuminating edges and adding dimension.
6. Deep Sea Blue - 
                            
                            #2C4A5D
                         - A dark, rich blue that serves as a shadow, providing contrast and enhancing the three-dimensional quality of illustrations.
7. Dark Slate Green - 
                            
                            #2D4C5A
                         - A very dark shade with green undertones that can be used for pronounced shadows, giving depth and elegance.

This color palette showcases a variety of shades based on the base color 4B6F8D, including rim light and shadow options. The combination of soft and deep tones allows for a balanced design, ideal for creating depth and dimension in your illustrations.

What specific elements of your illustration do you plan to apply these shades to? Are there any particular styles or moods you’re aiming to achieve with this palette?