@marcella: You can change the color code as per your need and then add the following CSS in “Appearance => Theme Options => Custom CSS” box.
#main-slider .entry-title span { color: #222; }
I see that you are using Catch Everest Pro version. In this case, yes you can use page slider instead of Post slider. See the theme instruction page for more details http://catchthemes.com/theme-instructions/catch-everest-pro/
You can build custom menu from “Appearance => Menus” and can add custom links to menu. So, it can be any link.