Beamer 中頁腳的不同部分有不同的顏色？

Question

我想用不同的顏色修改頁腳的三個部分。這怎麼可能？在這裡，我的頁腳分為三個部分。

\documentclass[10pt,xcolor={dvipsnames}]{beamer}
\usefonttheme{professionalfonts}
\useoutertheme{infolines}

\mode<presentation> {

\usetheme{Frankfurt}
\usecolortheme{whale}


\setbeamercolor{section in head/foot}{bg=blue!0!black,fg=white}
% -------------------------------------------------------------------------------------------------------------------------------------
% footer
%\setbeamercolor{section in foot}{fg=white, bg=OliveGreen}
%\setbeamercolor{section in foot}{fg=white, bg=MidnightBlue}
\setbeamerfont{footline}{size=\fontsize{6}{6}\selectfont}
%\setbeamercolor{section in foot}{fg=white, bg=ForestGreen}
%\setbeamercolor{section in foot}{bg=blue!40!black,fg=white}
\setbeamercolor{section in foot}{fg=white, bg=BlueViolet}
\setbeamertemplate{footline}
{
 \hbox{%
  \begin{beamercolorbox}[wd=.25\paperwidth,ht=2.6ex,dp=1ex,center]{section in foot}%
    \usebeamerfont{section in foot}\insertshortauthor
  \end{beamercolorbox}%
  \begin{beamercolorbox}[wd=.4\paperwidth,ht=2.6ex,dp=1ex,center]{section in foot}%
    \usebeamerfont{section in foot}\insertsubtitle
  \end{beamercolorbox}%
  \begin{beamercolorbox}[wd=.35\paperwidth,ht=2.6ex,dp=1ex,center]{section in foot}%
    \usebeamerfont{section in foot} Stanford \text{    } \insertframenumber/\inserttotalframenumber
  \end{beamercolorbox}}% 

  \vskip0pt%
}

\setbeamertemplate{navigation symbols}{}
}


\subtitle{\hspace{20mm} Signal Processing}
\author{Stephen}
\date{March 3, 2017}
% ------------------------------------------------------------------------------------------------------------------------------------------
\usepackage{graphicx} % Allows including images
\usepackage{booktabs} % Allows the use of \toprule, \midrule and \bottomrule in tables


\begin{document}

\begin{frame}[plain]
\titlepage % Print the title page as the first slide
\end{frame}

\begin{frame}
\frametitle{Overview} % Table of contents slide, comment this block out to remove it
\tableofcontents % Throughout your presentation, if you choose to use \section{} and \subsection{} commands, these will automatically be printed on this slide as an overview of your presentation
\end{frame}



%------------------------------------------------

\begin{frame}
\Huge{\centerline{The End}}
\end{frame}

%----------------------------------------------------------------------------------------

\end{document}

Answer 1

\documentclass[10pt,xcolor={dvipsnames}]{beamer}
\usefonttheme{professionalfonts}
\useoutertheme{infolines}

\mode<presentation> {

\usetheme{Frankfurt}
\usecolortheme{whale}

\setbeamercolor{section in head/foot}{bg=blue!0!black,fg=white}

\setbeamerfont{footline}{size=\fontsize{6}{6}\selectfont}
\setbeamercolor{section in foot}{fg=white, bg=BlueViolet}
\setbeamercolor{subsection in foot}{fg=BlueViolet, bg=white}
\setbeamertemplate{footline}
{
 \hbox{%
  \begin{beamercolorbox}[wd=.25\paperwidth,ht=2.6ex,dp=1ex,center]{section in foot}%
    \usebeamerfont{section in foot}\insertshortauthor
  \end{beamercolorbox}%
  \begin{beamercolorbox}[wd=.4\paperwidth,ht=2.6ex,dp=1ex,center]{section in foot}%
    \usebeamerfont{section in foot}\insertsubtitle
  \end{beamercolorbox}%
  \begin{beamercolorbox}[wd=.35\paperwidth,ht=2.6ex,dp=1ex,center]{subsection in foot}%
    \usebeamerfont{section in foot} Stanford \text{    } \insertframenumber/\inserttotalframenumber
  \end{beamercolorbox}}%

  \vskip0pt%
}

\setbeamertemplate{navigation symbols}{}
}

\subtitle{\hspace{20mm} Signal Processing}
\author{Stephen}
\date{March 3, 2017}

\usepackage{graphicx}
\usepackage{booktabs}

\begin{document}

\begin{frame}[plain]
\titlepage
\end{frame}

\begin{frame}
\frametitle{Overview}
\tableofcontents
\end{frame}

\begin{frame}
\Huge{\centerline{The End}}
\end{frame}

\end{document}