Makes the poster theme coherent with the presentation

We do not use brown blocks any more, replaced by light gray

texinputs/beamerthemetptposter.sty

@@ -17,17 +17,18 @@
 % TPT colors
 \definecolor{tptred}{RGB}{191,18,56} 
 \definecolor{tptbrown}{RGB}{109,80,71}
+\colorlet{tptgray}{black!30}
 
 % some usefull beamer colors
 \setbeamercolor{structure}{fg=tptred}
-\setbeamercolor{block title}{parent=structure,bg=normal text.bg!75!tptbrown}
-\setbeamercolor{block body}{bg=normal text.bg!98!tptbrown}
+\setbeamercolor{block title}{parent=structure,bg=normal text.bg!75!tptgray}
+\setbeamercolor{block body}{bg=normal text.bg!98!tptgray}
 \setbeamercolor{block title alerted}{use={normal text,alerted text},fg=alerted text.fg!75!normal text.fg,bg=normal text.bg!75!tptred}
 \setbeamercolor{block body alerted}{bg=normal text.bg!95!tptred}
 \setbeamercolor{poster title}{fg=white,bg=tptred}
 \setbeamercolor{poster logo title}{fg=black,bg=white}
 
-\setbeamercolor{date in head/foot}{fg=white,bg=tptbrown}
+\setbeamercolor{date in head/foot}{fg=white,bg=tptgray}
 \setbeamercolor{page in head/foot}{fg=white,bg=tptred}
 \setbeamercolor{dept in head/foot}{fg=white,bg=black}