Here is a single color palette that evokes an inviting, trustworthy, welcoming, clear, productive, helpful, warm yet fun tone for a website:

1. Color Name: Tranquil Blue
   Hex Code: 
                            
                            #3C82B8
                        
   Description: This deep blue hue represents trustworthiness and reliability. It creates a sense of calmness and clarity, making it ideal for conveying a welcoming and inviting tone on the website.

2. Color Name: Golden Yellow
   Hex Code: 
                            
                            #FFC20E
                        
   Description: This vibrant yellow shade symbolizes warmth, friendliness, and optimism. It adds a touch of playfulness and fun to the palette while still conveying a welcoming and inviting atmosphere.

3. Color Name: Fresh Green
   Hex Code: 
                            
                            #6BBF59
                        
   Description: This refreshing green color represents productivity and growth. It creates a sense of clarity and vibrancy, making it perfect for emphasizing a clear and productive tone on the website.

4. Color Name: Pure White
   Hex Code: 
                            
                            #FFFFFF
                        
   Description: This pure white shade signifies cleanliness, simplicity, and helpfulness. It creates a sense of openness and approachability, making it ideal for conveying a helpful and welcoming tone on the website.

5. Color Name: Soft Gray
   Hex Code: 
                            
                            #CCCCCC
                        
   Description: This soft gray hue represents neutrality and balance. It adds a touch of sophistication and professionalism to the palette while still maintaining a warm and welcoming atmosphere.

6. Color Name: Coral Pink
   Hex Code: 
                            
                            #FF6F61
                        
   Description: This vibrant coral pink color symbolizes energy, enthusiasm, and friendliness. It adds a playful and fun element to the palette, creating a warm and inviting tone on the website.

Overall, this color palette combines shades of blue, yellow, green, white, gray, and coral pink to evoke an inviting, trustworthy, welcoming, clear, productive, helpful, warm yet fun tone for the website.