Complex sentence: The tentacles of anemones in deep or murky water can be a grey colour, but are otherwise usually a deep green colour with purple tips due to the presence of symbiotic algae within the tentacles that use sunlight as an energy source.
Split into simpler sentences: The tentacles of anemones in deep or murky water can be a grey colour but are otherwise usually a deep green colour with purple tips. This is due to the presence of symbiotic algae within the tentacles that use sunlight as an energy source.