My hostname is localhost, reported by hostname command, and terminal prompt root@localhost:~#.

How can i change it to mismis.com with mismis alias? and what is the proper configuration.

I confused after reading some articles on web.

My /etc/hosts:

127.0.0.1       localhost
127.0.1.1       srv345.myweb.com      srv345
178.162.231.61  janstone.mismis.com    janstone
# The following lines are desirable for IPv6 capable hosts
::1     localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters



Question: Changing color and header of beamer with CambridgeUS
Answer: To change the color for the frame title and for the title and subtitle, you need to redefine the beamer colors frametitle and title:

\setbeamercolor{frametitle}{&lt;color&gt;}
\setbeamercolor{title}{&lt;color&gt;}


to change the position of the headers, you need to redefine the headline template as defined in the outer theme infolines (internally used by CambridgeUS). Here's the original definition:

\defbeamertemplate*{headline}{infolines theme}
{
  \leavevmode%
  \hbox{%
  \begin{beamercolorbox}[wd=.5\paperwidth,ht=2.65ex,dp=1.5ex,right]{section in head/foot}%
    \usebeamerfont{section in head/foot}\insertsectionhead\hspace*{2ex}
  \end{beamercolorbox}%
  \begin{beamercolorbox}[wd=.5\paperwidth,ht=2.65ex,dp=1.5ex,left]{subsection in head/foot}%
    \usebeamerfont{subsection in head/foot}\hspace*{2ex}\insertsubsectionhead
  \end{beamercolorbox}}%
  \vskip0pt%
}


As you can see, the alignment for the first beamercolorbox is right, and the one for the second box is left: you can change these as you wish. 

In the following example I used a shade of cyan for the titles (not the best choice) and I used center for both boxes in the headline:

\documentclass{beamer}

\usetheme{CambridgeUS}


% Set Color ==============================

% Custom colors
\usepackage{xcolor}

% http://www.computerhope.com/htmcolor.htm
\definecolor{gold}{HTML}{FDD017}
\definecolor{deep sky blue}{HTML}{3BB9FF}
\definecolor{light sky blue}{HTML}{82CAFA}

\definecolor{mybackground}{HTML}{82CAFA}
\definecolor{myforeground}{HTML}{0000A0}

\setbeamercolor{normal text}{fg=black,bg=white}
\setbeamercolor{alerted text}{fg=red}
\setbeamercolor{example text}{fg=black}

\setbeamercolor{background canvas}{fg=myforeground, bg=white}
\setbeamercolor{background}{fg=myforeground, bg=mybackground}

\setbeamercolor{palette primary}{fg=black, bg=gray!30!white}
\setbeamercolor{palette secondary}{fg=black, bg=gray!20!white}
\setbeamercolor{palette tertiary}{fg=black, bg=gold}

\setbeamercolor{frametitle}{fg=cyan!80!black}
\setbeamercolor{title}{fg=cyan!80!black}

\setbeamertemplate{headline}
{
  \leavevmode%
  \hbox{%
  \begin{beamercolorbox}[wd=.5\paperwidth,ht=2.65ex,dp=1.5ex,center]{section in head/foot}%
    \usebeamerfont{section in head/foot}\insertsectionhead\hspace*{2ex}
  \end{beamercolorbox}%
  \begin{beamercolorbox}[wd=.5\paperwidth,ht=2.65ex,dp=1.5ex,center]{subsection in head/foot}%
    \usebeamerfont{subsection in head/foot}\hspace*{2ex}\insertsubsectionhead
  \end{beamercolorbox}}%
  \vskip0pt%
}

% Set Color ==============================

\title{Title1}
\subtitle{Title2}
\author{Author}
\institute{Institute}
\date{Date}


\begin{document}

\frame{\maketitle}

\section[Outline]{}
\frame{\tableofcontents}

\section{Header1}
\subsection{Header2}
\frame{\frametitle{Topic1}
%
HTML color codes are the \textbf{hexadecimal triplets} representing the colors red, green, and blue.
%
These color codes can be used to change the color of the background, text, and tables on a web page.
}

\end{document}