Hover on title

This should do the trick:

.entry-title a:hover {
    color: #xxxxxx;
}

Replace xxxxxx with any shade you like: http://0to255.com/

Because of the way CSS inheritance works, you may need to add !important just before the semicolon to have it take effect on your theme, so you’d have:

.entry-title a:hover {
    color: #xxxxxx !important;
}

If you’re not using a child theme, an easy way to add custom CSS is to activate Jetpack’s Custom CSS module. This way, your CSS won’t be overwritten when you update the theme.

Let me know how it goes!