Here is a 16-color rainbow palette designed specifically for spreadsheet highlighting, ensuring that all colors have an acceptable contrast ratio with black text. The colors are desaturated to maintain readability without the need for white text.

json
{
  "palette_name": "Desaturated Rainbow Palette",
  "colors": [
    {
      "name": "Desaturated Red",
      "hex_code": "
          
          #C47C7C
       "
    },
    {
      "name": "Desaturated Orange",
      "hex_code": "
          
          #D1A76D
       "
    },
    {
      "name": "Desaturated Yellow",
      "hex_code": "
          
          #D1D17D
       "
    },
    {
      "name": "Desaturated Lime",
      "hex_code": "
          
          #A4C77D
       "
    },
    {
      "name": "Desaturated Green",
      "hex_code": "
          
          #7DC77D
       "
    },
    {
      "name": "Desaturated Cyan",
      "hex_code": "
          
          #7DC7C7
       "
    },
    {
      "name": "Desaturated Blue",
      "hex_code": "
          
          #7D9DC7
       "
    },
    {
      "name": "Desaturated Indigo",
      "hex_code": "
          
          #7D7DC7
       "
    },
    {
      "name": "Desaturated Violet",
      "hex_code": "
          
          #A57DC7
       "
    },
    {
      "name": "Desaturated Magenta",
      "hex_code": "
          
          #C77DC7
       "
    },
    {
      "name": "Desaturated Rose",
      "hex_code": "
          
          #C77DA5
       "
    },
    {
      "name": "Desaturated Coral",
      "hex_code": "
          
          #C77D8E
       "
    },
    {
      "name": "Desaturated Peach",
      "hex_code": "
          
          #D1A77D
       "
    },
    {
      "name": "Desaturated Mint",
      "hex_code": "
          
          #A7D1A7
       "
    },
    {
      "name": "Desaturated Periwinkle",
      "hex_code": "
          
          #A7B7D1
       "
    },
    {
      "name": "Desaturated Plum",
      "hex_code": "
          
          #BDA7D1
       "
    }
  ]
}

This palette offers a variety of colors while maintaining a desaturated tone, making it suitable for use with black text in spreadsheets.

Would you like to know more about how to apply this palette, or do you have any specific colors in mind that you’d like to adjust?