Colour

Distinctive green of north Norris basin

Minute geyser orange (south Norris Basin)
Around the hot pools it mostly seemed to be yellow flowers. I'm not qualified to comment on how many different species.
The clear blue pool surrounded by pristine white was new since 6 monthe before when we last visited. Makes me want to live rather nearer Yellowstone!
West Thumb green and blue
Mammoth Terraces blue and orange