Here is a color palette inspired by a dark-themed navigation app with marine elements, featuring indigo, turquoise, and contrasting colors for text:

json
{
  "palette_name": "Marine Navigation",
  "colors": [
    {
      "name": "Deep Indigo",
      "hex_code": "
          
          #4B0082
       "
    },
    {
      "name": "Turquoise Blue",
      "hex_code": "
          
          #40E0D0
       "
    },
    {
      "name": "Coral Red",
      "hex_code": "
          
          #FF4040
       "
    },
    {
      "name": "Seafoam Green",
      "hex_code": "
          
          #2E8B57
       "
    },
    {
      "name": "Bright White",
      "hex_code": "
          
          #FFFFFF
       "
    }
  ]
}

This palette combines deep marine hues with vibrant contrasting colors for text to ensure readability against a dark background. The indigo and turquoise provide a soothing yet modern aesthetic, while the coral red and bright white offer striking contrasts for important information.

Would you like to see how these colors work together in design, or do you have any specific elements you want to include in your app?