Here is a pastel rainbow color palette that combines soft, light colors, making it visually appealing while still maintaining the essence of a rainbow. This palette should be easier on the eyes but more vibrant than a muted palette.

json
{
  "palette_name": "Pastel Rainbow Years in Excel",
  "colors": [
    {
      "name": "Pastel Red",
      "hex_code": "
                            
                            #FFB3B3
                        "
    },
    {
      "name": "Pastel Orange",
      "hex_code": "
                            
                            #FFCC99
                        "
    },
    {
      "name": "Pastel Yellow",
      "hex_code": "
                            
                            #FFFF99
                        "
    },
    {
      "name": "Pastel Green",
      "hex_code": "
                            
                            #B3FFB3
                        "
    },
    {
      "name": "Pastel Blue",
      "hex_code": "
                            
                            #99CCFF
                        "
    },
    {
      "name": "Pastel Indigo",
      "hex_code": "
                            
                            #CC99FF
                        "
    },
    {
      "name": "Pastel Violet",
      "hex_code": "
                            
                            #EAB8E4
                        "
    },
    {
      "name": "Pastel Pink",
      "hex_code": "
                            
                            #FFB3E6
                        "
    },
    {
      "name": "Pastel Teal",
      "hex_code": "
                            
                            #99FFFF
                        "
    },
    {
      "name": "Pastel Lavender",
      "hex_code": "
                            
                            #D3B2E6
                        "
    }
  ]
}

This pastel rainbow palette offers a lovely balance of soft colors suitable for representing each year in your Excel sheets. Would you like to make any adjustments or explore further options?