If you go into your style sheet in the editor, Control + F to find the CSS rule for "featured-text" and change the text color from #fff to the color of the slider. That is the easiest way to remove it without delving into the code too much.
There's no point changing the theme's files because you'll just lose that change when the theme updates. There's also a chance that the style doesn't exist, because text is aligned left by default.
If you want to make CSS changes, you can do so through a Custom CSS Manager plugin.
If you don't know the actual CSS, try querying a forum like http://csscreator.com/forum
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