\documentclass[aspectratio=169]{beamer}
% Document metadata
\title{Trigon theme}
\subtitle{A modern, elegant and versatile theme for Beamer}
\author[TL]{Thomas Lambert}
\institute{Univeristy of Liège}
\date{\today}
% Image for the title page (use includegraphics option to properly size/place it)
\titlegraphic{\includegraphics[height=\paperheight]{library.jpg}}
\usetheme[sectionstyle=style2]{trigon}
% Define logos to use (comment if no logo)
\biglogo{trigon_full.pdf} % Used on titlepage only
\smalllogo{trigon_small.pdf} % Used on top right corner of regular frames
% ------ If you want to change the theme default colors, do it here ------
%\definecolor{tPrim}{HTML}{00843B} % Green
%\definecolor{tSec}{HTML}{289B38} % Green light
%\definecolor{tAccent}{HTML}{F07F3C} % Orange
% ------ Packages and definitions used for this demo. Can be removed ------
\usepackage{appendixnumberbeamer} % To use \appendix command
\pdfstringdefDisableCommands{% Fix hyperref translate warning with \appendix
\def\translate#1{#1}%
}
\usepackage{pgf-pie} % For pie charts
\usepackage{caption} % For subfigures
\usepackage{subcaption} % For subfigures
\usepackage{xspace}
\newcommand{\themename}{\textbf{\textsc{trigon}}\xspace}
\usepackage[scale=2]{ccicons} % Icons for CC-BY-SA
\usepackage{booktabs} % Better tables
%==============================================================================
% BEGIN DOCUMENT
%==============================================================================
\begin{document}
\include{frames}
\end{document}