Here is the revised color palette with Purple Heart adjusted to be slightly lighter than Rebecca Purple:

json
{
  "palette_name": "Adjusted Transition from Lightest to Darkest",
  "colors": [
    {
      "name": "Amethyst",
      "hex_code": "
                            
                            #9966CC
                        "
    },
    {
      "name": "Royal Purple",
      "hex_code": "
                            
                            #7851A9
                        "
    },
    {
      "name": "Medium Purple",
      "hex_code": "
                            
                            #9370DB
                        "
    },
    {
      "name": "Purple Heart",
      "hex_code": "
                            
                            #7D3C98
                        "
    },
    {
      "name": "Rebecca Purple",
      "hex_code": "
                            
                            #663399
                        "
    }
  ]
}

In this palette, Purple Heart has been adjusted to a lighter shade ( #7D3C98 ), ensuring it is slightly lighter than Rebecca Purple while keeping the overall flow of the palette intact.

Would you like to make any other modifications or need assistance with something else?