Here is a soft rainbow color palette based on your request:

json
{
  "palette_name": "Soft Rainbow Palette",
  "colors": [
    {
      "name": "Soft Pink",
      "hex_code": "
          
          #F5A3B6
       "
    },
    {
      "name": "Lavender Purple",
      "hex_code": "
          
          #D4C5E4
       "
    },
    {
      "name": "Mint Green",
      "hex_code": "
          
          #A8E5B2
       "
    },
    {
      "name": "Sky Blue",
      "hex_code": "
          
          #A2C8E1
       "
    },
    {
      "name": "Soft Teal",
      "hex_code": "
          
          #A2D4D4
       "
    },
    {
      "name": "Peach Orange",
      "hex_code": "
          
          #F2B2A2
       "
    },
    {
      "name": "Light Indigo",
      "hex_code": "
          
          #A2A6E1
       "
    }
  ]
}

This palette features softer shades of the colors you requested, making it suitable for a gentle and pleasing visual in Excel. Would you like to see variations of any specific color or additional suggestions for your project?