Vistaprint help with color customization

[Oscar_Ernie]

I'm working on my pre-travel brochures and need some help. I've chosen one of their templates, but can't for the life of me figure out how to change the background colors. I've seen that others here have definitely done that...I'm wondering how? I'm aware that you can download a generic brochure template to Photoshop or Illustrator, but I don't have either-and besides, I like their pre-made choices. It's enough work getting all the wording lined up and sized properly! =) So, changing the font colors is easy, but I'm totally stuck when it comes to the background! Can anyone tell me how they did it? TIA!