Update small things

org/presentations.org

@@ -4,6 +4,7 @@
 #+LANGUAGE: de
 #+OPTIONS: toc:t H:2
 #+BEAMER_THEME: Singapore
+#+BEAMER_COLOR_THEME: rose
 
 #+COLUMNS: %40ITEM %10BEAMER_env(Env) %9BEAMER_envargs(Env Args) %4BEAMER_col(Col) %10BEAMER_extra(Extra)