1) Seven million is estimated, although I am struggling to imagine how this could have been determined.
2) Smell.
3) Light, culture, time.
4) 'Green with envy' for jealous, and 'tickled pink' for very happy.
5) Dark blue would work.
6) An assortment of vibrant ones.
7) Mental breakdown - psychosis.
8) Earthy rusty red.
9) Red.
10) Pink.