Here’s a color palette that includes both warm and cool colors from the full spectrum. The warm colors include shades like red, orange, and yellow, while the cool colors include shades like blue, green, and purple.

json
{
  "palette_name": "Warm and Cool Spectrum",
  "colors": [
    {
      "name": "Red",
      "hex_code": "
                            
                            #FF0000
                        "
    },
    {
      "name": "Orange",
      "hex_code": "
                            
                            #FFA500
                        "
    },
    {
      "name": "Yellow",
      "hex_code": "
                            
                            #FFFF00
                        "
    },
    {
      "name": "Green",
      "hex_code": "
                            
                            #008000
                        "
    },
    {
      "name": "Cyan",
      "hex_code": "
                            
                            #00FFFF
                        "
    },
    {
      "name": "Blue",
      "hex_code": "
                            
                            #0000FF
                        "
    },
    {
      "name": "Purple",
      "hex_code": "
                            
                            #800080
                        "
    },
    {
      "name": "Pink",
      "hex_code": "
                            
                            #FFC0CB
                        "
    }
  ]
}

This palette features a diverse range of colors that balance the warmth of reds and yellows with the coolness of blues and greens.

For your request of generating a PNG with each color as 20x20 pixels and a total size of 512x512 pixels, please note that I can’t create images directly. However, you can easily create such an image using graphic design software by creating a grid layout for these colors. Would you like guidance on how to create that image?