Use raised buttons to add dimension to otherwise mostly flat layouts, e.g. in long busy lists of content, or in wide spaces. Avoid using raised buttons on already-raised content such as dialogs or cards.If onPressed and onLongPress callbacks are null, then the button will be disabled and by default will resemble a flat button in the disabledColor. If you are trying to change the button’s color and it is not having any effect, check that you are passing a non-null onPressed or onLongPress callbacks.