Answer:
What can be measured but not seen?
A precious fluid, thicker than water.
If you happen to wear one of these warm garments around, you might get doused in red paint.
Sharp and long, flag of the world. What is it?
I look at you, you look at me, I raise my right, you raise your left.
Iām grown from darkness but shine with a pale light. Very round I am and always a lady's delight.