well i know that certain octipuses change color and live around coral and barrier reefs.
chemical barrier
food most likely wont change the colour of your teeth but drinking coffee will stain your teeth and make it a kind of brown-ish colour.
a
Well their not creatures their babies just a form of animation
coral, and plants
Fish
a physical barrier!!!
quota
Litmus contains organic chemicals that have a particular colour (some kind of red) when protonated - that is, in acidic conditions - but a different colour (blue) when in basic conditions or when they have donated protons. We see this colour change and can identify whether a solution is nonacidic or nonbasic by using one of these strips.
Hurricanes and typhoons occur in the Great Barrier Reef.
Literary characters.
change of state change of colour fizzing/gas bubbles