Here is a color palette based on your request for blues, greens, and greys suitable for a stacked bar chart:

json
{
  "palette_name": "Blue Green Grey Palette",
  "colors": [
    {
      "name": "Sky Blue",
      "hex_code": "
                            
                            #87CEEB
                        "
    },
    {
      "name": "Steel Blue",
      "hex_code": "
                            
                            #4682B4
                        "
    },
    {
      "name": "Dodger Blue",
      "hex_code": "
                            
                            #1E90FF
                        "
    },
    {
      "name": "Medium Sea Green",
      "hex_code": "
                            
                            #3CB371
                        "
    },
    {
      "name": "Sea Green",
      "hex_code": "
                            
                            #2E8B57
                        "
    },
    {
      "name": "Light Sea Green",
      "hex_code": "
                            
                            #20B2AA
                        "
    },
    {
      "name": "Light Sky Blue",
      "hex_code": "
                            
                            #87CEFA
                        "
    },
    {
      "name": "Pale Turquoise",
      "hex_code": "
                            
                            #AFEEEE
                        "
    },
    {
      "name": "Teal",
      "hex_code": "
                            
                            #008080
                        "
    },
    {
      "name": "Slate Grey",
      "hex_code": "
                            
                            #708090
                        "
    },
    {
      "name": "Charcoal Grey",
      "hex_code": "
                            
                            #36454F
                        "
    },
    {
      "name": "Gainsboro",
      "hex_code": "
                            
                            #DCDCDC
                        "
    },
    {
      "name": "Light Grey",
      "hex_code": "
                            
                            #D3D3D3
                        "
    },
    {
      "name": "Dark Slate Grey",
      "hex_code": "
                            
                            #2F4F4F
                        "
    },
    {
      "name": "Dark Cyan",
      "hex_code": "
                            
                            #008B8B
                        "
    }
  ]
}

This palette provides a range of blues, greens, and greys that should work well for differentiating elements in your stacked bar chart.

Would you like to know how to apply these colors in your charting library, or do you have any other questions?