Here’s a new color palette for your Gantt chart, avoiding both red and green, while still providing softer colors to distinguish each of your four projects:

 < Soft Project Color Palette Without Red and Green >
1. Project Light Blue - 
                            
                            #A8D8E6
                         - A gentle light blue that promotes a sense of calm and clarity, perfect for a project that requires focus.
2. Project Soft Yellow - 
                            
                            #F9EBAE
                         - A warm soft yellow that brings a sense of optimism and cheerfulness, suitable for uplifting project representation.
3. Project Blush Pink - 
                            
                            #F2C6D4
                         - A delicate blush pink that conveys warmth and approachability, ideal for a project centered on collaboration.
4. Project Lavender Gray - 
                            
                            #D5C4E2
                         - A muted lavender gray that signifies creativity and sophistication, fitting for a project that encourages innovation.

This palette avoids both red and green while maintaining a soft and professional aesthetic for your Gantt chart.

Would you like to add any specific project themes or icons to accompany these colors? Or do you have other features in mind for your chart?