My favorite color is blue, there's so many pretty shades to choose from.
Blue is also my favorite color.  How many shades of blue are there?
I'm not sure but it covers all the colors between violet and green on the spectrum of visible light.
Wow, that's interesting.  What else do you know about blue?
I know that distant objects appear more blue because of an optical effect called "atmospheric perspective"
That sounds wild.  Where did blue come from like dyes?
addition of salt to produce a lake pigment.
Natural vs synthetic.
The majority of natural dyes are derived from plant sources: roots, berries, bark, leaves, wood, fungi and lichens. Most dyes are synthetic, i.e., are man-made from petrochemicals. Other than pigmentation, they have a range of applications including organic dye lasers, optical media (CD-R) and camera sensors (color filter array).
History.
Textile dyeing dates back to the Neolithic period. Throughout history
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Blue is the colour of light between violet and green on the visible spectrum. Hues of blue include indigo and ultramarine, closer to violet; pure blue, without any mixture of other colours; Cyan, which is midway in the spectrum between blue and green, and the other blue-greens turquoise, teal, and aquamarine.
Blue also varies in shade or tint; darker shades of blue contain black or grey, while lighter tints contain white. Darker shades of blue include ultramarine, cobalt blue, navy