Can't change theme of ZSH in Ubuntu 12.04

I have changed the theme in my ~/.zshrc file however whilst some of the colors in the prompt change the text size and background color remain as the Ubuntu default. Any one know how I can override this to make my terminal purse ZSH with the correct theme. My .bashrc looks like this

# ~/.bashrc: executed by bash(1) for non-login shells.
# see /usr/share/doc/bash/examples/startup-files (in the package bash-doc)
# for examples

# If not running interactively, don't do anything
[ -z "$PS1" ] && return

# don't put duplicate lines or lines starting with space in the history.
# See bash(1) for more options
HISTCONTROL=ignoreboth

# append to the history file, don't overwrite it
shopt -s histappend

# for setting history length see HISTSIZE and HISTFILESIZE in bash(1)
HISTSIZE=1000
HISTFILESIZE=2000

# check the window size after each command and, if necessary,
# update the values of LINES and COLUMNS.
shopt -s checkwinsize

# If set, the pattern "**" used in a pathname expansion context will
# match all files and zero or more directories and subdirectories.
#shopt -s globstar

# make less more friendly for non-text input files, see lesspipe(1)
[ -x /usr/bin/lesspipe ] && eval "$(SHELL=/bin/sh lesspipe)"

# set variable identifying the chroot you work in (used in the prompt below)
if [ -z "$debian_chroot" ] && [ -r /etc/debian_chroot ]; then
debian_chroot=$(cat /etc/debian_chroot)
fi

# set a fancy prompt (non-color, unless we know we "want" color)
case "$TERM" in
xterm-color) color_prompt=yes;;
esac

# uncomment for a colored prompt, if the terminal has the capability; turned
# off by default to not distract the user: the focus in a terminal window
# should be on the output of commands, not on the prompt
#force_color_prompt=yes

if [ -n "$force_color_prompt" ]; then
  if [ -x /usr/bin/tput ] && tput setaf 1 >&/dev/null; then
 # We have color support; assume it's compliant with Ecma-48
 # (ISO/IEC-6429). (Lack of such support is extremely rare, and such
 # a case would tend to support setf rather than setaf.)
 color_prompt=yes
else
color_prompt=
  fi
fi

if [ "$color_prompt" = yes ]; then
PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\          [\033[01;34m\]\w\[\033[00m\]\$ '
else
PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
fi
unset color_prompt force_color_prompt

# If this is an xterm set the title to user@host:dir
case "$TERM" in
xterm*|rxvt*)
PS1="\[\e]0;${debian_chroot:+($debian_chroot)}\u@\h: \w\a\]$PS1"
;;
*)
;;
esac

# enable color support of ls and also add handy aliases
if [ -x /usr/bin/dircolors ]; then
test -r ~/.dircolors && eval "$(dircolors -b ~/.dircolors)" || eval "$(dircolors -b)"
alias ls='ls --color=auto'
#alias dir='dir --color=auto'
#alias vdir='vdir --color=auto'

alias grep='grep --color=auto'
alias fgrep='fgrep --color=auto'
alias egrep='egrep --color=auto'
fi

# some more ls aliases
alias ll='ls -alF'
alias la='ls -A'
alias l='ls -CF'

# Add an "alert" alias for long running commands.  Use like so:
#   sleep 10; alert
alias alert='notify-send --urgency=low -i "$([ $? = 0 ] && echo terminal || echo                    error)" "$(history|tail -n1|sed -e '\''s/^\s*[0-9]\+\s*//;s/[;&|]\
s*alert$//'\'')"'

# Alias definitions.
# You may want to put all your additions into a separate file like
# ~/.bash_aliases, instead of adding them here directly.
# See /usr/share/doc/bash-doc/examples in the bash-doc package.

if [ -f ~/.bash_aliases ]; then
. ~/.bash_aliases
fi

# enable programmable completion features (you don't need to enable
# this, if it's already enabled in /etc/bash.bashrc and /etc/profile
# sources /etc/bash.bashrc).
if [ -f /etc/bash_completion ] && ! shopt -oq posix; then
. /etc/bash_completion
fi

PATH=$PATH:$HOME/.rvm/bin # Add RVM to PATH for scripting

And my .zshrc looks like this:

# Path to your oh-my-zsh configuration.
ZSH=$HOME/.oh-my-zsh

# Set name of the theme to load.
# Look in ~/.oh-my-zsh/themes/
# Optionally, if you set this to "random", it'll load a random theme each
# time that oh-my-zsh is loaded.
ZSH_THEME="dallas"

# Example aliases
# alias zshconfig="mate ~/.zshrc"
# alias ohmyzsh="mate ~/.oh-my-zsh"

# Set to this to use case-sensitive completion
# CASE_SENSITIVE="true"

# Comment this out to disable weekly auto-update checks
# DISABLE_AUTO_UPDATE="true"

# Uncomment following line if you want to disable colors in ls
# DISABLE_LS_COLORS="true"

# Uncomment following line if you want to disable autosetting terminal title.
# DISABLE_AUTO_TITLE="true"

# Uncomment following line if you want red dots to be displayed while waiting for     completion
# COMPLETION_WAITING_DOTS="true"

# Which plugins would you like to load? (plugins can be found in ~/.oh-my-   zsh/plugins/*)
# Custom plugins may be added to ~/.oh-my-zsh/custom/plugins/
# Example format: plugins=(rails git textmate ruby lighthouse)
plugins=(git)

source $ZSH/oh-my-zsh.sh

# Customize to your needs...
export PATH=/home/toaksie/.rvm/gems/ruby-1.9.3-p194/bin:/home/toaksie/.rvm/gems/ruby-1.9.3-p194@global/bin:/home/toaksie/.rvm/rubies/ruby-1.9.3-p194/bin:/home/toaksie/.rvm/bin:/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games

Any help much appreciated!