Remove colour in text area on slider

You should create a Child theme to make your changes. If you do not, all of your changes will be lost if you update your theme.

Here is some CSS that might get you started:

.coda-nav { background-color: #FFFFFF !important; }
.coda-nav ul li a { color: #FF0000 !important; border-left: 2px solid #000000; }
.coda-nav ul li a.current { color: #000000 !important; background-color: #FFFFDE !important; }
.coda-slider { box-shadow: none !important; }

Add this to the end of style.css in your child theme folder.