Interface Buttons

What is your requirement? Where are these buttons going to be used? 

Below is a sample how you could manipulate the style of the button or or you can use the similar logic at the color parameter.

a!localVariables(
  local!values:{1,2,3,4},
  local!selection:0,
  a!buttonArrayLayout(
    buttons: a!forEach(
      items: local!values,
      expression: a!buttonWidget(
        label: concat("button"," ",fv!item),
        value: fv!item,
        saveInto: local!selection,
        style: if(
          local!selection=fv!item,
          "SOLID",
          "OUTLINE"
        )
      )
    )
  )
)

your value that is being saved would evaluate the color. here I have written in a!forEach() for understanding. But if you share us the details on where and what an accurate solution can be provided.

What is your requirement? Where are these buttons going to be used? 

Below is a sample how you could manipulate the style of the button or or you can use the similar logic at the color parameter.

a!localVariables(
  local!values:{1,2,3,4},
  local!selection:0,
  a!buttonArrayLayout(
    buttons: a!forEach(
      items: local!values,
      expression: a!buttonWidget(
        label: concat("button"," ",fv!item),
        value: fv!item,
        saveInto: local!selection,
        style: if(
          local!selection=fv!item,
          "SOLID",
          "OUTLINE"
        )
      )
    )
  )
)

your value that is being saved would evaluate the color. here I have written in a!forEach() for understanding. But if you share us the details on where and what an accurate solution can be provided.

Thank you for the code.
Actually I was doing some mistake in logic but now it worked.