I never meet many of my clients in person. They send me photos and/or video and I "virtually" help them up their visual game . Here is one of the mistakes I see all the time!
This is a panel of speakers (not my clients). Does anybody stand out? Not really, in fact it's the water bottles grab my attention.
Now look at this panel
Notice where you eye is drawn. The woman in the orange top! It doesn't matter who's got the microphone, your eye will wander to the person wearing color.
This is valuable information. Nobody can truly hear your message if part of their brain is elsewhere. However, you can have the focus be on you even when you aren't speaking. You can be "selling" without ever opening your mouth! Of course, you want to make sure your color is in sync with the core message your business.