Change "Blog post" color

Hi, the link you gave for your site doesn’t work, so I assume you are talking about this page: http://zamfitnessperformance.co.uk/blog/?

Are you referring to the blog titles like “Why Cardio Sucks”? Right now, the theme is using an image as a background:
images/title-bg.gif

So, assuming you are using a child theme or that you are using a Custom CSS Plugin, you will need to change your background here:

#primaryContent h1.postTitle a, #primaryContent h2.postTitle a {
    background: url("images/title-bg.gif") repeat scroll 0 0 #000000;
    border-radius: 10px 10px 10px 10px;
    color: #FFFFFF;
    font-size: 24px;
    font-weight: normal;
    line-height: 1.5em;
    padding: 10px 15px;
    text-shadow: -1px -1px #333333;
    text-transform: uppercase;
}

and either replace the image, or take it out and change your color with the hex code.

Hope this helps.