I use the code below to reduce the height of the frametitle box in beamer. But this also makes the frametitle shading I had disappear (gradient from red to black) that is now uniformly red and not progressively shaded. How can I change that?

Example shaded but too high frametitle box:

\documentclass[pdftex,10pt,,xcolor=dvipsnames]{beamer}

\usetheme{Warsaw}
\usecolortheme[RGB={200,0,0}]{structure}

\begin{document}
\begin{frame}
\frametitle{\large Bla Bla}
\begin{itemize}
\item First
\item Second
\end{itemize}
\end{frame}
\end{document}


Example frametitle box OK but not shaded:

\documentclass[pdftex,10pt,,xcolor=dvipsnames]{beamer}

\usetheme{Warsaw}
\usecolortheme[RGB={200,0,0}]{structure}

\setbeamertemplate{frametitle}{
\nointerlineskip
\begin{beamercolorbox}[wd=\paperwidth,ht=2ex,dp=0.7ex]{frametitle}
\hspace*{1ex}\insertframetitle
\end{beamercolorbox}}

\begin{document}
\begin{frame}
\frametitle{\large Bla Bla}
\begin{itemize}
\item First
\item Second
\end{itemize}
\end{frame}
\end{document}


Thank you.

You don't need to change anything about the definition of the frametitle, just don't manually mess with the font size, but use beamers own font mechanism.

\documentclass[pdftex,10pt,,xcolor=dvipsnames]{beamer}

\usetheme{Warsaw}
\usecolortheme[RGB={200,0,0}]{structure}