beamer
uses \insertslideintonotes
to insert a frame thumbnail into notes page. This command is defined in beamerbasenotes.sty
file:
\newcommand{\insertslideintonotes}[1]{{%
\begin{pgfpicture}{0cm}{0cm}{#1\paperwidth}{#1\paperheight}
\begin{pgflowlevelscope}{\pgftransformscale{#1}}%
\color{normal text.bg}
\pgfpathrectangle{\pgfpointorigin}{\pgfpoint{\paperwidth}{\paperheight}}
\pgfusepath{fill}
\color{normal text.fg}
{\pgftransformshift{\pgfpoint{\beamer@origlmargin}{\footheight}}\pgftext[left,bottom]{\copy\beamer@frameboxcopy}}
\end{pgflowlevelscope}
\end{pgfpicture}%
}}
As you can see, it draws a background rectangle with color normal text.bg
and the frame contents (stored in \beamer@frameboxcopy
) is added in normal text.fg
color.
Thus, you need to force normal text.bg
color to be like the one used in note page
. As I don't know what could be the effect of changing normal text
color, another solution would be to change \insertslideintonotes
definition and use the color you want as background just there. This can be done with next code:
\documentclass[notes]{beamer}
\usepackage{blindtext}
\makeatletter
\renewcommand{\insertslideintonotes}[1]{{%
\begin{pgfpicture}{0cm}{0cm}{#1\paperwidth}{#1\paperheight}
\begin{pgflowlevelscope}{\pgftransformscale{#1}}%
\color{blue!40} %<-------- Change color here
\pgfpathrectangle{\pgfpointorigin}{\pgfpoint{\paperwidth}{\paperheight}}
\pgfusepath{fill}
\color{normal text.fg}
{\pgftransformshift{\pgfpoint{\beamer@origlmargin}{\footheight}}\pgftext[left,bottom]{\copy\beamer@frameboxcopy}}
\end{pgflowlevelscope}
\end{pgfpicture}%
}}
\makeatother
\setbeameroption{show notes}
\setbeamercolor{note page}{bg=red!30}
\setbeamercolor{background canvas}{bg=blue!40}
\setbeamercolor{normal text}{fg=white}
\begin{document}
\begin{frame}
\blindtext
\end{frame}
\note[itemize]
{\item First note
\item Second note.}
\end{document}

\documentclass
to \end{document}`. Making reference to all themes and packages you use, to show the problem.