How to exclude active titles from the link color
Usually, when you add a Posts widget in your layout, the Post titles are active links. For this reason they inherit the link color. In many cases though, you want to exclude the posts (or any other custom post type title) from the link color, and have it inherit the standard text color.
This is what the Do not apply link color on active titles switch does, which is located at the Tools tab in your Style Kits.