As with any decisions you make when choosing tops for your headshot session, it’s important to start by considering your casting and who you are as an actor. Think about what you want your headshots to say about you.
First of all, any photographer would probably rather you bring more tops than necessary so always err on the side of caution and bring plenty.
With regards to colours think about your hair colour and skin tone – what shows you (and most importantly your eyes) off the best? Blue tops really bring out blue eyes; green and brown tops bring out green eyes. A white top can be good against dark skin but can wash out someone with fair colourings, however can look great as a top underneath something else – more on that here.
A very general rule is to think in terms of muted and calmer tones instead of very bright colours. The latter is fine to bring but it says something very specific and doesn’t work for everyone. Patterns are fine but avoid bringing anything with contrasting colours (red and green for eg) or big logos or pictures on as that may pull focus away from you.
Black is also fine to bring – it generally works for everyone, is simple and classic but it can also be quite neutral and doesn’t say much about the actor.
It’s a good idea to go through photographers websites and look at pictures of people of similar casting and colouring to you for inspiration on top colours.
And if you’ve got a top you love but are unsure if it’ll work, bring it anyway – your photographer will be able to tell you.