documentclass[17pt]{extarticle}
usepackage{extsizes}
usepackage{lipsum}
usepackage{xcolor}
usepackage{fancyhdr}
usepackage{fontspec}
usepackage{tikz}

% To set the font and formatting:

setmainfont{[lcars.ttf]} %To load the font named lcars
%setmainfont[AutoFakeBold=1.5, AutoFakeSlant=0.4]{lcars.ttf} % To set bold or italics if I wanted to.

% LCARS Colours begin:

% Sources for colours:
% http://lcarsmania.com/designguide/Okudagrams_Color.png
% http://www.lcarscom.net/lcars_colors.gif

definecolor{LCARSBG}{HTML}{000000} % Pure black
definecolor{LCARSTCMain}{HTML}{FF9900} %Dark yellow
definecolor{LCARSTC1}{HTML}{CC99CC} % Light purple
definecolor{LCARSTC2}{HTML}{9999CC} % Light blue
definecolor{LCARSTC3}{HTML}{CC6666} % Light red
definecolor{LCARSTC4}{HTML}{FFCC99} % Light peach
definecolor{LCARSTC5}{HTML}{9999FF} % Light blue, a different variant
definecolor{LCARSTC6}{HTML}{FF9966} % Light orange
definecolor{LCARSTC7}{HTML}{CC6699} % Pink
definecolor{LCARSTC8}{HTML}{F5173C} % Light red
% LCARS Colours end.

% To set page numbers to the right colour and style.

makeatletter
fancypagestyle{mypagestyle}{%
  fancyhf{}% Clear header/footer
  fancyfoot[C]{textcolor{LCARSTCMain}{thepage}}% Page # in middle/centre of footer
  renewcommand{footrulewidth}{0pt}% No footer rule
  deffootrule{{if@fancyplainletfootrulewidthplainfootrulewidthfi
    vskip-footruleskipvskip-footrulewidth
    hrule@widthheadwidth@heightfootrulewidthvskipfootruleskip}}
}
makeatother
pagestyle{mypagestyle}

begin{document}
begin{flushleft}

pagecolor{LCARSBG} % Page background colour.
color{LCARSTCMain} % Main body text colour.

section*{textcolor{LCARSTC5}{Section Title:}}

textcolor{LCARSTC8}{A question or subheading here?}newline

textcolor{LCARSTC6}{Another sub heading:}newline

lipsum[1]
begin{tikzpicture}
draw[rounded corners] (0, 0) rectangle (4, 1) {};
end{tikzpicture}

end{flushleft}

end{document}