Here is the updated color palette with a darker and more suitable shade replacing Dark Lavender:

json
{
  "palette_name": "Adjusted Transition with Medium Purple First",
  "colors": [
    {
      "name": "Medium Purple",
      "hex_code": "
                            
                            #9370DB
                        "
    },
    {
      "name": "Amethyst",
      "hex_code": "
                            
                            #9966CC
                        "
    },
    {
      "name": "Royal Purple",
      "hex_code": "
                            
                            #7851A9
                        "
    },
    {
      "name": "Purple Plum",
      "hex_code": "
                            
                            #A65E9E
                        "
    },
    {
      "name": "Rebecca Purple",
      "hex_code": "
                            
                            #663399
                        "
    }
  ]
}

In this palette, Purple Plum has been chosen for its darker tone, providing a better fit in the transition between Royal Purple and Rebecca Purple.

Would you like to make any further adjustments or explore how to use this palette?