Here is the updated color palette with one accent color added, while still keeping the overall subdued and professional look suitable for an Excel chart:

json
{
  "palette_name": "Subtle Earth Tones with Accent",
  "colors": [
    {
      "name": "Muted Sage",
      "hex_code": "
          
          #B7C9A5
       "
    },
    {
      "name": "Sage Green",
      "hex_code": "
          
          #A3BFAF
       "
    },
    {
      "name": "Dusty Blue",
      "hex_code": "
          
          #A3B7C9
       "
    },
    {
      "name": "Soft Blue",
      "hex_code": "
          
          #8DA3B7
       "
    },
    {
      "name": "Warm Gray",
      "hex_code": "
          
          #B0B3B8
       "
    },
    {
      "name": "Light Gray",
      "hex_code": "
          
          #D1D3D4
       "
    },
    {
      "name": "Muted Brick",
      "hex_code": "
          
          #C84A3D
       "
    },
    {
      "name": "Soft Brick",
      "hex_code": "
          
          #D67F6D
       "
    },
    {
      "name": "Accent Olive",
      "hex_code": "
          
          #7D8B2A
       "
    }
  ]
}

This palette, “Subtle Earth Tones with Accent,” includes an olive green accent color that can be used to highlight important data points or sections in your Excel chart, adding a touch of vibrancy while still maintaining a professional look.

Would you like suggestions on how to best utilize the accent color in your chart?