Here is a color palette based on your request for the 7 colors of the rainbow, white, and a background color.

json
{
  "palette_name": "Rainbow Spectrum with White",
  "colors": [
    {
      "name": "Red",
      "hex_code": "
          
          #FF0000
       "
    },
    {
      "name": "Orange",
      "hex_code": "
          
          #FFA500
       "
    },
    {
      "name": "Yellow",
      "hex_code": "
          
          #FFFF00
       "
    },
    {
      "name": "Green",
      "hex_code": "
          
          #008000
       "
    },
    {
      "name": "Blue",
      "hex_code": "
          
          #0000FF
       "
    },
    {
      "name": "Indigo",
      "hex_code": "
          
          #4B0082
       "
    },
    {
      "name": "Violet",
      "hex_code": "
          
          #EE82EE
       "
    },
    {
      "name": "White",
      "hex_code": "
          
          #FFFFFF
       "
    },
    {
      "name": "Background Color",
      "hex_code": "
          
          #F0F8FF
       "
    }
  ]
}

This palette features the vibrant colors of the rainbow alongside white and a light background color for contrast.

Would you like to know more about how to use this palette in design, or do you have any specific applications in mind?