I have had people people ask about what to wear when scheduling a family portrait session. There are many different options depending on your style. There is the matching approach, two traditional options are jeans with black shirts or khakis with white shirts. Another option if matching is not your thing is to have every one wear colors that go together but don't "match" such as bold or pastel colors or have everyone wear different shades of the same color.
If you want a second opinion on a clothing choice feel free to ask me about it in our pre session consultation.