Apparently some setting in your Emacs Live setup overrides the loaded theme's background-color.
As you are a new to Emacs, I heartily recommend that you start with an empty init file and go from there.
Not because those starter kits are bad, some are in fact rather beautiful, but it's much harder to troubleshoot problems in some big starter kit, than if you start with a clean init.el and gradually add stuff. If things stop working then, you know exactly what you did, and you can easily revert those changes.
Without knowing for what you are using Emacs, a minimal emacs setup could look like this:
An empty folder
This folder contains the file
init.el with the following contents:
(setq package-enable-at-startup nil)
(add-to-list 'package-archives '("melpa" . "http://melpa.org/packages/"))
This enables the melpa package archive.
Now you have access to ~2.500 packages, among them gems like magit, use-package, paredit, flycheck, company, expand-region, avy, ... .