Colore classe beamer

Ciao a tutti,
Come potete vedere da qui, sto lavorando ad una nuova classe beamer.
Con i consigli ricevuti, posso cambiare combinazione di colore in un solo e fluido gesto.
Quello che ora mi piacerebbe fare, sarebbe mettere una combinazione colori multipla… nel senso che la footline, divisa in 3 parti, vorrei colorarla di 3 colori diversi, e due per la testata. In particolare vorrei usare i colori della bandiera italiana, quindi una footline verde bianco rossa (testo nero o bianco a seconda del contrasto) e una headline verde rossa (testo bianco). La parte del titolo andrebbe bianca con testo nero.

Qui metto il codice della classe nella parte dei colori:`\NeedsTeXFormat{LaTeX2e}
\ProvidesClass{colorbeamer}[2009/11/15 v0.1 Mirko's version of Beamer]

\chardef\f@ur=4

\DeclareOption{red}{\def\colorbeamer@color{red}\chardef\colorbeamer@colnumber\z@}
\DeclareOption{green}{\def\colorbeamer@color{green}\chardef\colorbeamer@colnumber\@ne}
\DeclareOption{blue}{\def\colorbeamer@color{blue}\chardef\colorbeamer@colnumber\tw@}
\DeclareOption{yellow}{\def\colorbeamer@color{yellow}\chardef\colorbeamer@colnumber\thr@@}
\DeclareOption{italy}{\def\colorbeamer@color{italy}\chardef\colorbeamer@colnumber\f@ur}

\DeclareOption{bibbook}{\def\colorbeamer@bib{book}\chardef\colorbeamer@bibnumber\z@}
\DeclareOption{bibart}{\def\colorbeamer@bib{art}\chardef\colorbeamer@bibnumber\@ne}

\PassOptionsToPackage{svgnames}{xcolor}
\PassOptionsToClass{hyperref={pdfpagelabels=false}}{beamer}

\ExecuteOptions{green,bibart}
\DeclareOption*{\PassOptionsToClass{\CurrentOption}{beamer}}

\ProcessOptions\relax

\LoadClass{beamer}%[2005/06/12]

\RequirePackage{isodate}
\RequirePackage{guit}%[2006/05/24]
\GuITcolor{1,.66,1,0}
\hypersetup{colorlinks=false}

%Layout grafico

\renewcommand{\fontsubfuzz}{1pt}

% Configurazioni di beamer
\usetheme{Warsaw}
\beamertemplatenumberedballsectiontoc
%\usecolortheme[rgb={.5,0,0}]{structure}

\useoutertheme{split}
\usefonttheme{default}

\ifcase\colorbeamer@colnumber
%Rosso
\usecolortheme[rgb={.5,0,0}]{structure}
\or
%Verde
\usecolortheme[rgb={0,.5,0}]{structure}
\or
%Blu
\usecolortheme[rgb={0,0,.5}]{structure}
\or
%Giallo
\usecolortheme[rgb={1,.7,0}]{structure}
\or
%Italy
\usecolortheme[rgb={0,.75,0}]{structure}
\else
\PackageWarning{colorbeamer}{Unknown color, switching to default}
\usecolortheme[rgb={0,.5,0}]{structure}
\fi

\ifcase\colorbeamer@bibnumber
%Book
\setbeamertemplate{bibliography item}[book]
\or
%Article
\setbeamertemplate{bibliography item}[article]
\else
\PackageWarning{colorbeamer}{Unknown bibliography style, switching to default}
\setbeamertemplate{bibliography item}[article]
\fi

\setbeamertemplate{theorems}[numbered]
\newtheorem{teorema}[theorem]{Teorema}
\renewcommand{\qedsymbol}{{\emph{\footnotesize Q.E.D.}}}

%%% Colori dei blocchi di codice
\definecolor{LC background}{rgb}{1,.97,.86}
\colorlet{LC foreground}{DarkBlue}
\colorlet{LC alerted fg}{DarkRed}

\setbeamercolor{normal text}{bg=gray!20}
%\mode{\setbeamercolor{normal text}{bg=white}}
\mode{\setbeamercolor{normal text}{bg=white}}

\ifcase\colorbeamer@colnumber
%Rosso
\setbeamercolor{alerted text}{fg=Crimson}
\setbeamercolor{example text}{fg=Tomato}
\setbeamercolor{block title}{bg=Red}
\setbeamercolor{block body}{bg=block title.bg!20}
\setbeamercolor{block title alerted}{fg=Coral!10,bg=Coral}
\setbeamercolor{block body alerted}{bg=block title alerted.bg!20}
\setbeamercolor{block title example}{fg=white,bg=OrangeRed}
\setbeamercolor{block body example}{bg=block title example.bg!20}
\setbeamercolor{LaTeX code}{fg=LC foreground,bg=LC background}
\setbeamercolor{alerted LaTeX code}{fg=LC alerted fg,bg=LC background}
\or
%Verde
\setbeamercolor{alerted text}{fg=Teal}
\setbeamercolor{example text}{fg=Green}
\setbeamercolor{block title}{bg=ForestGreen}
\setbeamercolor{block body}{bg=block title.bg!20}
\setbeamercolor{block title alerted}{fg=Lime!10,bg=Lime}
\setbeamercolor{block body alerted}{bg=block title alerted.bg!20}
\setbeamercolor{block title example}{fg=white,bg=MediumSeaGreen}
%\setbeamercolor{block title example}{fg=white,bg=SeaGreen}
\setbeamercolor{block body example}{bg=block title example.bg!20}
\setbeamercolor{LaTeX code}{fg=LC foreground,bg=LC background}
\setbeamercolor{alerted LaTeX code}{fg=LC alerted fg,bg=LC background}
\or
%Blu
\setbeamercolor{alerted text}{fg=NavyBlue}
\setbeamercolor{example text}{fg=Blue}
\setbeamercolor{block title}{bg=DodgerBlue}
\setbeamercolor{block body}{bg=block title.bg!20}
\setbeamercolor{block title alerted}{fg=Cyan!10,bg=Cyan}
\setbeamercolor{block body alerted}{bg=block title alerted.bg!20}
\setbeamercolor{block title example}{fg=white,bg=Navy}
\setbeamercolor{block body example}{bg=block title example.bg!20}
\setbeamercolor{LaTeX code}{fg=LC foreground,bg=LC background}
\setbeamercolor{alerted LaTeX code}{fg=LC alerted fg,bg=LC background}
\or
%Giallo
\setbeamercolor{alerted text}{fg=Orange}
\setbeamercolor{example text}{fg=Goldenrod}
\setbeamercolor{block title}{bg=Gold}
\setbeamercolor{block body}{bg=block title.bg!20}
\setbeamercolor{block title alerted}{fg=OrangeRed!10,bg=OrangeRed}
\setbeamercolor{block body alerted}{bg=block title alerted.bg!20}
\setbeamercolor{block title example}{fg=white,bg=Goldenrod!80}
\setbeamercolor{block body example}{bg=block title example.bg!20}
\setbeamercolor{LaTeX code}{fg=LC foreground,bg=LC background}
\setbeamercolor{alerted LaTeX code}{fg=LC alerted fg,bg=LC background}
\or
%Italy TESTING
\setbeamercolor{alerted text}{fg=Crimson}
\setbeamercolor{example text}{fg=Green}
\setbeamercolor{block title}{bg=Gold}
\setbeamercolor{block body}{bg=block title.bg!20}
\setbeamercolor{block title alerted}{fg=Coral!10,bg=Coral}
\setbeamercolor{block body alerted}{bg=block title alerted.bg!20}
\setbeamercolor{block title example}{fg=white,bg=MediumSeaGreen}
\setbeamercolor{block body example}{bg=block title example.bg!20}
\setbeamercolor{LaTeX code}{fg=LC foreground,bg=LC background}
\setbeamercolor{alerted LaTeX code}{fg=LC alerted fg,bg=LC background}
\else
%Default
\setbeamercolor{alerted text}{fg=Teal}
\setbeamercolor{example text}{fg=Green}
\setbeamercolor{block title}{bg=ForestGreen}
\setbeamercolor{block body}{bg=block title.bg!20}
\setbeamercolor{block title alerted}{fg=Lime!10,bg=Lime}
\setbeamercolor{block body alerted}{bg=block title alerted.bg!20}
\setbeamercolor{block title example}{fg=white,bg=MediumSeaGreen}
%\setbeamercolor{block title example}{fg=white,bg=SeaGreen}
\setbeamercolor{block body example}{bg=block title example.bg!20}
\setbeamercolor{LaTeX code}{fg=LC foreground,bg=LC background}
\setbeamercolor{alerted LaTeX code}{fg=LC alerted fg,bg=LC background}
\fi

%%% Ridefinisco la footline
\setbeamertemplate{footline}{\leavevmode%
\begin{beamercolorbox}[wd=.33\paperwidth,ht=2.25ex,dp=1ex,leftskip=4pt plus 1pt,rightskip=4pt plus 1pt]{subsection in head/foot}
\insertshortauthor\hfill\insertshortinstitute
\end{beamercolorbox}%
\begin{beamercolorbox}[wd=.34\paperwidth,center,ht=2.25ex,dp=1ex]{section in head/foot}
\usebeamercolor[fg]{section in foot/head}\insertshorttitle
\end{beamercolorbox}%
\begin{beamercolorbox}[wd=.33\paperwidth,ht=2.25ex,dp=1ex,leftskip=4pt plus 1pt,rightskip=4pt plus 1pt]{subsection in head/foot}
\insertshortdate\hfill\insertframenumber/\inserttotalframenumber
\end{beamercolorbox}%
}`

Sapreste darmi una mano?

Grazie e buona serata.