I believe an educational/technical website should be clean without a bunch of moving buttons, twinkles and distractions like that. The set-up here look fine to me, pretending I just went looking for a coleoptera and found this page. It is more inviting than most insect and bug sites which are either "just for kids" or seem too abundant in text, with a sketch or two and "maybe" a decent photo image. Yes, navigation is vital and should be uncomplicated with links easy to find and follow. IMO For the informative site you offer, I like the clean lines and know the images will be top rate. Colors look fine to me with no suggestion about your choices. Tom.