Change colour of page titles

I have set the background colour on my site to black. The page titles (home, contact, about etc) are set to black by default by the theme. How do I change them to white (or another colour?)

At the moment I have added a heading block in with the names in white font, but the original headings can still be faintly seen above them.

website is


Hey there

You can use this css code to change all heading to white:

h1, h2, h3, h4, h5, h6 {
    color: #ffffff;