How do I change the color of the author text in the Title (first) frame?

Question

\documentclass[T]{beamer}

\usetheme{Frankfurt}
\usecolortheme{orchid}
\usefonttheme{structuresmallcapsserif}
\usefonttheme{serif}
\usepackage{multicol}
\usepackage{graphicx}

\title{Example Presentation}
\author{Author 1\\Author 2}
\date{\today}

\begin{document}

{\usebackgroundtemplate
{\includegraphics[width=\paperwidth,height=\paperheight]{caestitlepage}}
\begin{frame}
    \titlepage
\end{frame}

\end{document}

What changes would I need to make in order to make the "author text" white??

Answer 1

You just have to use the proper color template (author in this case); for example:

\setbeamercolor{author}{fg=white} 

A complete example (with a dummy background):

\documentclass[T]{beamer}
\usepackage{lmodern} % for font size substitution
\usetheme{Frankfurt}
\usecolortheme{orchid}
\usefonttheme{structuresmallcapsserif}
\usefonttheme{serif}
\usepackage{multicol}
\usepackage{tikz} %for dummy background

\title{Example Presentation}
\setbeamercolor{author}{fg=white}
\author{Author 1\\ Author 2}
\date{\today}

\begin{document}

\setbeamertemplate{background}{\tikz\fill[blue,opacity=0.4](0,0)rectangle(\paperwidth,\paperheight);]}

%{\usebackgroundtemplate
%{\includegraphics[width=\paperwidth,height=\paperheight]{caestitlepage}}

\begin{frame}
    \titlepage
\end{frame}

\end{document}

The result:

Actually, also percusse's suggestion is fine; indeed:

\documentclass[T]{beamer}
\usepackage{lmodern} % for font size substitution
\usetheme{Frankfurt}
\usecolortheme{orchid}
\usefonttheme{structuresmallcapsserif}
\usefonttheme{serif}
\usepackage{multicol}
\usepackage{tikz} %for dummy background

\title{Example Presentation}
\author{\textcolor{white}{Author 1}\\ \textcolor{white}{Author 2}}
\date{\today}

\begin{document}

\setbeamertemplate{background}{\tikz\fill[blue,opacity=0.4](0,0)rectangle(\paperwidth,\paperheight);]}

%{\usebackgroundtemplate
%{\includegraphics[width=\paperwidth,height=\paperheight]{caestitlepage}}

\begin{frame}
    \titlepage
\end{frame}

\end{document}

provides the same picture reported above.