Beamer: changing background color leaves white lines above and below title

It must be simple but I don't find the last missing bit. I'm making a beamer presentation where I want single slides with a different background color.

However, when I set the background color using \setbeamercolor{normal text}{bg=red} or \setbeamercolor{background canvas}{bg=red}, there are still two white horizontal lines surrounding the frame title and I cannot find out how to change the color of those or how to remove them.

Even using [plain] for the frame does not get rid of those.

Below is a working example.

\documentclass[handout]{beamer}
\usepackage{color}
\usecolortheme{rose}
\useoutertheme{smoothbars}
\begin{document}
\begin{frame}
\frametitle{slide 1}
first
\end{frame}
{
\setbeamercolor{normal text}{bg=yellow!20}
\begin{frame}
\frametitle{slide 2}
second
\end{frame}
}
\end{document}

• You don't need outerthemes for header and footer and color package. Comment those out and it should work fine. – percusse Sep 17 '13 at 9:53
• As @percusse said, the line to comment is (if I understood right) \useoutertheme{smoothbars}, try to complile because for me it worked well. – alandella Sep 17 '13 at 9:56
• Man, some relict from some early template I copied. Shame on me. Thanks so much for the help, deleting \useoutertheme{smoothbars} exactly solved my problem. – Werner Sep 17 '13 at 10:13
• @AndreaL. Can you write up an answer? – percusse Sep 17 '13 at 12:04
• @percusse Yes, sure. – alandella Sep 17 '13 at 12:08

As stated in the comments, the adding of \useoutertheme{smoothbars} tends to be the main reason of the problem, so commenting the lines gives for the code:

\documentclass[handout]{beamer}
\usecolortheme{rose}
\begin{document}
\begin{frame}
\frametitle{slide 1}
first
\end{frame}
{
\setbeamercolor{normal text}{bg=yellow!20}
\begin{frame}
\frametitle{slide 2}
second
\end{frame}
}
\end{document}


A working example with the output:

That basically solves the issue.