October Blues

1. In poison dart frogs, bright blue colors broadcast a warning to predators that the animal is _______
3. A material that produces a color depending on which wavelengths of visible light it absorbs and which it reflects
4. A blue mineral mentioned in the article
7. A synonym for rare, used in the first paragraph of the article
11. the type of light visible at 400 nanometers
12. The subject of this article
14. The vivid blue pigment ground from lapis lazuli
16. The highest points on a wave
17. A blue flower mentioned in the article
18. The lowest points on a wave
19. Blue animals' colors rely on ______ to create a blue appearance

2. each of our eyes contains between 6 million and 7 million light-sensitive cells called ________
5. platypus fur glows in vivid shades of blue and green when exposed to ______ rays, a form of light not visible to the human eye
6. The cornflower absorbs this color
8. the distance between two of the highest points or two of the lowest points on a wave
9. Light that we do not see is absorbed off of objects, while light that we do see _______ off of objects
10. The earliest use of blue dye was recorded in this country
13. Light is a form of energy that travels in ______
15. Known as the blue planet