Transparent color in beamercolorbox

Question

I am using a template style for my beamer presentation. It has the nice feature of two color bars at the top and bottom. I would really like to make these bars somewhat transparent.

I tried to change this part of the style file, which should be it, but then it stopped working.

   \setbeamertemplate{footline}
    {%
      \ifnum\c@framenumber=1
      \else
        \begin{beamercolorbox}[wd=0.95\paperwidth,right,dp=2ex]{page number}
        \insertframenumber/\inserttotalframenumber
        \end{beamercolorbox}
        \fi%
      \begin{beamercolorbox}[colsep=1.25pt]{lower separation line foot}
      \end{beamercolorbox}
    }

Here is the MWE

\documentclass[11pt]{beamer}

\usetheme{bjeldak.sty}
\setbeamertemplate{navigation symbols}[horizontal]

\title{MWE}
\author{ME}
\date{\today}


\begin{document}
  {%
    \setbeamertemplate{headline}{}
    \frame{\titlepage}
  }
  
\begin{frame}{Hello}
Hi     
\end{frame}

\end{document}

And here is the style file which is called "beamerthemebjeldak.sty.sty" in my folder:

% Insipired by Cameron Bracken's theme originally posted
% here: http://cameron.bracken.bz/beamer-template
% January 2009

% Modifications done by Martin Bjeldbak Madsen 
% June 2014
\mode<presentation>

\RequirePackage{palatino}
\RequirePackage{mathpazo}
\usepackage{transparent}

\useoutertheme[subsection=false,shadow]{miniframes}
\useinnertheme{default}
\usefonttheme{serif}

\setbeamertemplate{footline}
{%
  \ifnum\c@framenumber=1
  \else
    \begin{beamercolorbox}[wd=0.95\paperwidth,right,dp=2ex]{page number}
    \insertframenumber/\inserttotalframenumber
    \end{beamercolorbox}
    \fi%
  \begin{beamercolorbox}[colsep=1.25pt]{lower separation line foot}
  \end{beamercolorbox}
}

% Display a slide before the current section with overview inf
\AtBeginSection[]
{%
   \begin{frame}
       \frametitle{Overview}
       \tableofcontents[currentsection,hideothersubsections]
   \end{frame}
}

\setbeamerfont{title like}{shape=\scshape}
\setbeamerfont{frametitle}{shape=\scshape}
\setbeamerfont{section in head/foot}{shape=\scshape,size=\tiny}

\setbeamertemplate{navigation symbols}{} % hide bottom nav buttons
\setbeamercovered{transparent} % don't hide strip-teased bullet points

\definecolor{barcolor}{RGB}{238,123,0}
\setbeamercolor{lower separation line head}{bg=barcolor} 
\setbeamercolor{lower separation line foot}{bg=barcolor} 
\setbeamercolor{normal text}{fg=black,bg=white} 
\setbeamercolor{alerted text}{fg=red} 
\setbeamercolor{example text}{fg=black} 
\setbeamercolor{structure}{fg=black} 
\setbeamercolor{palette tertiary}{fg=black,bg=black!10} 
\setbeamercolor{palette quaternary}{fg=black,bg=black!10} 

\mode<all>

Answer 1

Beamer uses pgf to draw these boxes. So you can influence their opacity by changing the \pgfsetfillopacity

\documentclass[11pt]{beamer}
\usetheme{bjeldak}

\addtobeamertemplate{footline}{\pgfsetfillopacity{0.5}}{  \pgfsetfillopacity{1}}
\addtobeamertemplate{headline}{\pgfsetfillopacity{0.5}}{  \pgfsetfillopacity{1}}

\title{MWE}
\author{ME}
\date{\today}

\begin{document}
  {%
    \setbeamertemplate{headline}{}
    \frame{\titlepage}
  }
  
\begin{frame}{Hello}
Hi     
\end{frame}

\end{document}