thanks in advance..

Code: Select all
\documentclass{beamer}
\usetheme{Darmstadt}
\definecolor{colboxcolor}{HTML}{003D50}
\usecolortheme[named=colboxcolor]{structure}
\usepackage{xcolor} % Extended colors
\usepackage{color} % Color extended names
\setbeamercolor*{palette secondary}{use=structure,fg=white,bg=colboxcolor}
\setbeamercolor*{palette tertiary}{use=structure,fg=white,bg=colboxcolor}
\begin{document}
\section{Introduction}
\subsection{One}
\begin{frame} text \end{frame}
\end{document}