Enhance contrast in Beamer Colortheme
On most presenters in class rooms the active (sub)section is not readable caused by the white font on yellow background. The contrast might be acceptable on pdf's on screen but not practical in a presentation.
Proposition: Change font to BFH-Gray on yellow background for nice contrast
"beamercolorthemeBFH.sty" 109L \setbeamercolor{section in sidebar}{fg=BFH-Gray,bg=BFH-Orange}