Here is a color palette based on your request for a dark theme with the primary color #3498DB , secondary color #673AB7 , and a background color of #1B1B1B :

json
{
  "palette_name": "Dark Theme with Blue and Purple Accents",
  "colors": [
    {
      "name": "Primary Blue",
      "hex_code": "
                            
                            #3498DB
                        "
    },
    {
      "name": "Secondary Purple",
      "hex_code": "
                            
                            #673AB7
                        "
    },
    {
      "name": "Background Black",
      "hex_code": "
                            
                            #1B1B1B
                        "
    },
    {
      "name": "Accent Gray",
      "hex_code": "
                            
                            #2C2C2C
                        "
    },
    {
      "name": "Text White",
      "hex_code": "
                            
                            #FFFFFF
                        "
    }
  ]
}

This palette features a striking combination of blue and purple against a dark background, providing a modern and vibrant look for a dark theme.

Do you need any additional suggestions for using this palette, or anything else you would like to know?