Here’s a pastel color palette suitable for an important Excel dashboard on a website:

 <Pastel Dashboard>
1. Soft Blue - 
                            
                            #A3C6E6
                         - A calming light blue that promotes clarity and focus.
2. Pale Green - 
                            
                            #B7E2D8
                         - A soothing green that enhances the feeling of balance and harmony.
3. Lavender - 
                            
                            #E3D7E7
                         - A gentle lavender that adds a touch of creativity without being overwhelming.
4. Light Peach - 
                            
                            #F4C3B2
                         - A warm peach that introduces a subtle warmth and approachability.
5. Soft Gray - 
                            
                            #D3D3D3
                         - A neutral gray that provides a solid background for data visualization.
6. Powder Pink - 
                            
                            #F5C2D2
                         - A soft pink that brings a friendly and inviting touch to the dashboard.
7. Mint Cream - 
                            
                            #F5FFFA
                         - A very light mint that adds freshness without distraction.
8. Light Lilac - 
                            
                            #E6D3E5
                         - A delicate lilac that complements the other colors while maintaining a soft aesthetic.

This pastel color palette is designed to create a calm and professional atmosphere, which is ideal for an important Excel dashboard. The colors are soft and muted, making it easy to digest information without overwhelming the viewer.

Would you like to see any variations or additional color suggestions? Or do you have specific elements in mind for the dashboard that might need particular colors?