Color Palette for Fantasy Koi Illustration:

1. Color Name: Sakura Pink
   Hex Code: 
          
          #FFA7D1
       
   Palette Description: A soft pastel pink reminiscent of cherry blossoms, adding a touch of delicacy and femininity to the illustration.

2. Color Name: Aquamarine
   Hex Code: 
          
          #7FFFD4
       
   Palette Description: A cool and refreshing shade of blue-green that represents the tranquil waters where the koi swim, evoking a sense of calm and serenity.

3. Color Name: Dreamy Lavender
   Hex Code: 
          
          #D6AEDD
       
   Palette Description: A gentle shade of purple that adds a dreamy and ethereal atmosphere to the illustration, giving it a mystical touch.

4. Color Name: Peachy Apricot
   Hex Code: 
          
          #FFCBA4
       
   Palette Description: A warm and soft orange hue with a hint of pink, resembling the vibrant hues of a sunset sky, adding warmth and energy to the artwork.

5. Color Name: Pastel Mint
   Hex Code: 
          
          #B2FAB4
       
   Palette Description: A muted and soothing shade of green, reminiscent of fresh mint leaves, creating a sense of tranquility and balance within the illustration.

6. Color Name: Cotton Candy Blue
   Hex Code: 
          
          #AED7FF
       
   Palette Description: A light and airy shade of blue, reminiscent of fluffy cotton candy, adding a touch of playfulness and whimsy to the artwork.

7. Color Name: Lavender Mist
   Hex Code: 
          
          #E6E6FA
       
   Palette Description: A pale and delicate shade of lavender, resembling a misty morning, adding a touch of mystery and enchantment to the illustration.

8. Color Name: Bubblegum Pink
   Hex Code: 
          
          #FFC0CB
       
   Palette Description: A vibrant and sugary pink, reminiscent of bubblegum, adding a pop of fun and excitement to the artwork.

9. Color Name: Golden Sunbeam
   Hex Code: 
          
          #FFD700
       
   Palette Description: A bright and radiant shade of gold, resembling a sunbeam, adding a touch of opulence and majesty to the illustration.