To complement the colors #fa3d59 (a vibrant pinkish-red) and #fffcfb (a soft off-white), I suggest adding #f6b93b , a warm golden yellow. This color enhances the palette by adding warmth and brightness without overpowering the existing colors.

Here is the new color palette in JSON format:

json
{
  "palette_name": "Bright Joy",
  "colors": [
    {
      "name": "Vibrant Pinkish-Red",
      "hex_code": "
                            
                            #fa3d59
                        "
    },
    {
      "name": "Soft Off-White",
      "hex_code": "
                            
                            #fffcfb
                        "
    },
    {
      "name": "Warm Golden Yellow",
      "hex_code": "
                            
                            #f6b93b
                        "
    }
  ]
}

This palette creates a lively and cheerful combination, with the vibrant pinkish-red bringing energy, the soft off-white providing a gentle base, and the warm golden yellow adding a touch of sunshine. Would you like to explore more palettes or different color combinations?