How to replace small icons in SharePoint Online lists via JSON

Question

For icons that display next to field names like so on lists:

How can we replace them with custom icons, or fluent UI icons?

My current JSON file for formatting the body, looks like this:

{
    "sections": [
        {
            "displayname": "About the Recipe",
            "fields": [
                "Title",
                "Number of views",
                "Author",
                "Publishing Date",
                "Description",
                "Nutrition Facts",
                "Number of ingredients",
                "Number of servings",
                "Calories per serving"
            ]
        },
        ....

Answer 1

This is not supported using JSON Formatting yet.

Unlike the header and the footer, body configuration only allows defining one or more sections and adding one or more columns into each of those sections.

Source: Configure custom body with one or more sections

Answer 2

List form not support using JSON Formatting. So, you can not change small icon of list columns.

You could refer to the following articles:

• Configure the list form
• Finally, SharePoint Received Form Formatting