This guide was originally provided by @ShahriarKh.

1. Install and enable the Obsidian Text Format plugin via Obsidian's Community Plugins store.
2. Use one of the following .json files for the list of mark style options:

• Basic (Recommended / Uses the options set in Style Settings)
• All Available Options (Ability to select different visual and text styles for each colour)

3. Open .obsidian/plugins/obsidian-text-format/data.json and add the styles:

{
  ...other options
  "WrapperList": [
    {
      "name": "Mark: Accent - Default - Default Text",
      "prefix": "<mark class=\" mark-default mark-text-default\">",
      "suffix": "</mark>"
    },
    {
      "name": "Mark: Accent - Border and Filled - Colored Text",
      "prefix": "<mark class=\" mark-borderandfilled mark-text-color\">",
      "suffix": "</mark>"
    },
    {
      "name": "Mark: Red - Default - Colored Text",
      "prefix": "<mark class=\"red mark-default mark-text-color\">",
      "suffix": "</mark>"
    },
    ...
]
}

Note: If the data.json file isn't there, go to Obsidian -> Settings -> Text Format tab under Community plugins in the sidebar -> Toggle one of the options On/Off which should cause the plugin to generate the data.json file.

4. 🛩 Restart Obsidian and Enjoy! You should now be able to find each option using the Command Palette.