I want to change checkbox custom field size and color with REST API

I have tried this json

"tabGroups": [

                        {

                            "groupLabel": "checkbox group",

                            "groupRule": "SelectAtLeast",

                            "minimumRequired": "1",

                            "maximumAllowed": "1",

                            "validationMessage": "Please check to indicate your agreement",

                            "tabScope": "document",

                            "pageNumber": "1",

                            "documentId": 8674

                        }

                    ],

                    "checkboxTabs": [

                        {

                            "anchorString": "Please check this box to acknowledge having read and understood the Zultys Equipment Rental Program Terms & Conditions as stated in this document.",

                            "tabLabel": "null",

                            "anchorXOffset": -26,

                            "anchorYOffset": 15,

                            "anchorUnits": "pixels",

                            "fontColor": "Green",

                            "tabGroupLabels": [

                                "checkbox group"

                            ]

                        }

                    ]

                }

There is not option so re-size a checkbox, but you can configure the formatting for text size and color, which can be leveraged to change the final appearance in the document.

The attribute names are fontColor and fontSize to be included in your JSON call. You can find the entire schema here to check what attributes are available and how the spelling needs to be.

The size and color of the checkboxes will only be visible after the recipient completed signing.

Example set up:

For the recipient the view does not reflect the color and size for the recipient:

This will actually result in the following output after signature: