Remove “Category:” and change menu color.

I've added a menu item for a specific posts category and when I select it it correctly displays all the posts in that category. In the middle of the page it also displays the header Category:Articles. I would like it to just display the category name "Articles". How do I do that? I would also like to change the color of the menu from white to black, but I can't find an option to do that in the theme.