How to set background color for an icon button?

You can achieve it with TextButton

    TextButton(
      style: TextButton.styleFrom(
        backgroundColor: colorScheme.primary,
        shape: CircleBorder(),
      ),
      child: Icon(
        MdiIcons.send,
        color: colorScheme.onPrimary,
      ),
      onPressed: () {},
    ),

The output will look like this:

You can use a Circular Avatar with the radius = text field's height/2 or whatever height you prefer.

To figure out text field specs you can visit material.io

So the chunk of code is going to be like the following:

CircleAvatar(
                radius: 30,
                backgroundColor: Color(0xff94d500),
                child: IconButton(
                  icon: Icon(
                    Icons.search,
                    color: Colors.black,
                  ),
                  onPressed: () {
                    ...
                  },
                ),
              ),

This way you get an Icon button with background color. I hope this can help you guys.

you can wrap your IconButton with Container and use color property to achieve desire output. May Following Example help You.

 suffixIcon: Container(
              color: Colors.green,
              child: new IconButton(
                  icon: new Icon(Icons.search,color: Colors.white,),onPressed: null),
            ),