beamerthemeOSAK: alert text color and colors in alert block

beamertheme/beamerthemeOSAK.sty

@@ -20,6 +20,9 @@
 \setbeamercolor{section number projected}{bg=darkred!80!gray}
 \setbeamertemplate{subsection in toc}[square]
 \setbeamercolor{subsection number projected}{bg=darkred!80!gray}
+\setbeamercolor{alerted text}{fg=red!90!black}
+\setbeamercolor{block title alerted}{bg=darkred, fg=white}
+\setbeamercolor{block body alerted}{bg=red!12!white}
 \beamertemplatenavigationsymbolsempty
 
 \logo{\includegraphics[height=2cm]{osak-logo}}