I'm always telling you to consider the context and the background of the setting you'll be speaking in (all black on Charlie Rose, bright sunlight at a state fair, etc) but sometimes it can be hard to picture what that will really be like.
Here's some video of Rep. Tammy Baldwin speaking at a black-tie dinner for the Human Rights Campaign. Or rather, video of video of her on large screens above the crowd. She wore purple:
You can barely see her standing on the stage, but you can certainly see her on the screens. Not only is the image large, it's repeated right next to itself. As much as I'm an advocate for prints, this would not be the right time! I think she chose well with a satin wrap around blouse with a subtle sheen.