Many of my students worry because they blush during their talks. If you too worry, you may like this video’s message: People will actually like you more if you blush.
If blushing still bothers you, no matter what, try wearing non-white shirts and tops. White clothing will only enhance the reddishness of your skin. Think Coca-Cola bottles. Then again: Why should something you cannot control or change, such as your skin color, bother you at all? Instead, worry about your content, your language, your style, your message. Worry about the things in a talk that matter.
Never be ashamed of the color of your skin.
The video also shows that ignoring Youtube comments may be best.