Based on the primary colors HEX 488BD1 (a calming blue), D76739 (a warm orange), and E0C849 (a vibrant yellow), I suggest a secondary color of HEX 4B8B3B, which is a refreshing green. This green complements the existing palette well and adds a natural feel to the character. For an accent color to pair with this secondary green, I recommend HEX A3C9E7, a soft sky blue that will harmonize with the main blue color while providing a subtle contrast.

Here’s the color palette in JSON format:

json
{
  "palette_name": "Character Color Palette",
  "colors": [
    {
      "name": "Main Blue",
      "hex_code": "
                            
                            #488BD1
                        "
    },
    {
      "name": "Warm Orange",
      "hex_code": "
                            
                            #D76739
                        "
    },
    {
      "name": "Vibrant Yellow",
      "hex_code": "
                            
                            #E0C849
                        "
    },
    {
      "name": "Refreshing Green",
      "hex_code": "
                            
                            #4B8B3B
                        "
    },
    {
      "name": "Soft Sky Blue",
      "hex_code": "
                            
                            #A3C9E7
                        "
    }
  ]
}

This palette combines the existing colors with a refreshing green and a soft sky blue for accents, creating a balanced and visually appealing scheme for your character. Would you like more suggestions or information on how to use these colors effectively?