Color Palette:

1. Bubblegum Pink
   Hex Code: 
                            
                            #FF69B4
                        
   Description: A vibrant and playful pink hue reminiscent of bubblegum, perfect for adding a feminine and fun touch to a birthday flyer.

2. Sunshine Yellow
   Hex Code: 
                            
                            #FFD700
                        
   Description: A bright and cheerful yellow shade that radiates warmth and happiness, ideal for conveying a joyful and celebratory atmosphere on a birthday flyer.

3. Sky Blue
   Hex Code: 
                            
                            #87CEEB
                        
   Description: A serene and calming blue reminiscent of the clear sky, great for creating a soothing and peaceful ambiance on a birthday flyer.

4. Mint Green
   Hex Code: 
                            
                            #98FF98
                        
   Description: A refreshing and invigorating shade of green, akin to the color of mint leaves, perfect for adding a touch of freshness and vitality to a birthday flyer.

5. Lavender Purple
   Hex Code: 
                            
                            #E6E6FA
                        
   Description: A soft and gentle shade of purple with hints of lilac, evoking a sense of tranquility and elegance, ideal for giving a refined and sophisticated look to a birthday flyer.

6. Fiesta Red
   Hex Code: 
                            
                            #FF4040
                        
   Description: A vibrant and fiery red hue reminiscent of festive celebrations, adding a bold and energetic element to a birthday flyer, perfect for catching attention and creating excitement.

Note: The provided hex codes and color names are subjective and may vary slightly depending on personal interpretation and device calibration.