You could use a sequence of steps like those given in the Answer by HansV in this thread, using your color instead of Bold and using brackets instead of quote marks. However, that would apply the same color to the brackets as to the found text.
If that's acceptable, you can stop there. To make the brackets not have the same font color, though, you would need additional steps to find colored brackets (left and right separately) and replace them with brackets with the black or Automatic. That's a bit tedious, so you can use the following macro (see http://www.gmayor.com/installing_macro.htm if needed) to do it all in one click.
Sub AddBrackets()
Dim rg As Range
Set rg = ActiveDocument.Range
With rg.Find
.Format = True
.Font.ColorIndex = wdRed ' replace as needed
.Replacement.Text = "{^&}"
.Execute Replace:=wdReplaceAll
End With
Set rg = ActiveDocument.Range
With rg.Find
.Text = "{"
.Format = True
.Font.ColorIndex = wdRed ' replace as needed
.Replacement.Font.ColorIndex = wdAuto
.Replacement.Text = "^&"
.Execute Replace:=wdReplaceAll
End With
Set rg = ActiveDocument.Range
With rg.Find
.Text = "}"
.Format = True
.Font.ColorIndex = wdRed ' replace as needed
.Replacement.Font.ColorIndex = wdAuto
.Replacement.Text = "^&"
.Execute Replace:=wdReplaceAll
End With
End Sub