Here is a color palette designed to represent three shades suitable for a stacked bar chart. The colors are selected to provide good contrast while maintaining a cohesive look.

json
{
  "palette_name": "Stacked Bar Shades",
  "colors": [
    {
      "name": "Light Blue",
      "hex_code": "
          
          #A3C4E0
       "
    },
    {
      "name": "Medium Blue",
      "hex_code": "
          
          #007BFF
       "
    },
    {
      "name": "Dark Blue",
      "hex_code": "
          
          #004085
       "
    }
  ]
}

This palette consists of three shades of blue, transitioning from light to dark, which can be visually appealing and easy to differentiate in a stacked bar chart.

Would you like any modifications or additional colors for this palette?