Here’s a color palette that fits your description, featuring a soft blue as the primary color, along with complementary colors for text and various shades, suitable for a Material 3 theme.

json
{
  "palette_name": "Soft Blue Material Theme",
  "colors": [
    {
      "name": "Soft Blue",
      "hex_code": "
                            
                            #A7C6ED
                        "
    },
    {
      "name": "Dark Blue",
      "hex_code": "
                            
                            #3F51B5
                        "
    },
    {
      "name": "Light Blue",
      "hex_code": "
                            
                            #E3F2FD
                        "
    },
    {
      "name": "Text White",
      "hex_code": "
                            
                            #FFFFFF
                        "
    },
    {
      "name": "Text Dark",
      "hex_code": "
                            
                            #212121
                        "
    },
    {
      "name": "Accent Blue",
      "hex_code": "
                            
                            #2196F3
                        "
    },
    {
      "name": "Gray",
      "hex_code": "
                            
                            #B0BEC5
                        "
    }
  ]
}

This palette includes a primary soft blue color for buttons, darker and lighter shades for versatility, and colors for text that will ensure good readability on your buttons.

Would you like to explore any specific shades or additional colors, or is there anything else you need for your theme?