Jukebox Fanworks Exchange

Go to https://www.dreamwidth.org/customize/ then select jukebox-fest instead of morbane from the dropdown at the top, then click "Customize your theme" from the box on the right. Click "Colors" in the link bar on the left, and play with the hex codes. I think "Entry title background color" might be what you're looking for, though you may have to hunt around a bit.