\usepackage{fancyhdr}
\pagestyle{fancy}
\usepackage{lastpage}
\renewcommand{\footrulewidth}{0.4pt}

\makeatletter
\patchcmd{\@fancyhead}{\rlap}{\color{gray}\rlap}{}{}
\patchcmd{\@fancyfoot}{\rlap}{\color{gray}\rlap}{}{}
\makeatother

\lhead{\color{gray}
	\GetTranslation{naglowekDane}
}
\chead{}
\rhead{\color{gray} \nrRaportu}
\lfoot{}
\cfoot{\scriptsize \color{gray} \GetTranslation{stopkaOswiadczenie}}
\rfoot{\color{gray} \GetTranslation{strona} \textbf{\thepage} \GetTranslation{stronaZ} \textbf{\pageref{LastPage}}}