[Theme: Food and Diet] How to Change Header Colors

For two months I’ve been trying to figure out how to change the color on my Food and Diet stylesheet. It comes with three choices, but they all have a salmon-orange color (#EF4D3C)and I’d prefer changing it to a blue (#003f7f). I’ve been through the style sheet many many times looking for the header colors, but can’t find them and can’t figure out how to change the colors other than just finding all of the #EF4D3C and hope it changes the headings.

Anyone familiar with the Food and Diet or have any suggestions? I’ve scoured the forums, but they say to find the “header” and change the color – which I’ve looked for and can’t find (except for background entry).
Thanks!