Toast toast = Toast.makeText(context, message, duration);
View view = toast.getView();
//Gets the actual oval background of the Toast then sets the colour filter
view.getBackground().setColorFilter(YOUR_BACKGROUND_COLOUR, PorterDuff.Mode.SRC_IN);
//Gets the TextView from the Toast so it can be editted
TextView text = view.findViewById(android.R.id.message);
text.setTextColor(YOUR_TEXT_COLOUR);
toast.show();