Color, value, and hue

Color is a term used for the whole subject, red, yellow, blue, green, orange and so on. Hues is used for pure spectrum colors. Value is the relative lightness and darkness of a color, it defines form and creates spatial illusions. Contrast of value separates objects in space.

Color wheel and RGB color wheel

If the visible portion of the light spectrum is divided into thirds, the predominant colors are red, green and blue. These three colors are considered the primary colors of the visible light spectrum.Primary colors can be arranged in a circle, commonly refered to as a color wheel. Red, green and blue (RGB) form a triangle on the color wheel. In between the primary colors are the secondary colors, cyan, magenta and yellow (CMY), which form another triangle.

Additive Color System (RGB).The additive color system involves light emitted directly from a source, before an object reflects the light. The additive reproduction process mixes various amounts of red, green and blue light to produce other colors. Combining one of these additive primary colors with another produces the additive secondary colors cyan, magenta, yellow. Combining all three primary colors produces white. Television and computer monitors create color using the primary colors of light. Each pixel on a monitor screen starts out as black. When the red, green and blue phosphors of a pixel are illuminated simultaneously, that pixel becomes white. This phenomenon is called additive color.

What, what, a fluorescent fish?

It took 3 years but Dr. Gong Zhiyuan, from the Department of Biological Sciences, and his team created a zebra fish that radiate a greenish glow under special light. Also they produced a fish that changes color when swimming through different temperature water. This fish became know as a Transgenic fish.
Briefly, the process involves injecting a green fluorescent protein that is isolated from jelly fish, onto the embryo of the Zebra fish which is cheap and easy to breed. This is known as micro-injection, using a very fine needle. In order for this to tbe successful, a suitable " fish gene promoter" must be identified. There are three kinds of promoters - one is skin specific, which means that the green fluorescent gene injected into the embryo will only affect the skin of the fish when the embryo develops. The second type is muscle-specific and the third type will enable a uniform colour in the entire fish. The research on treansgenic fish however, is not only for commercial purpose. It can also enable us to further understand the function ot the genepromoters. Because green colour is a convenient cellular marker, the green fluorescent treansgenic fish will facilitate cell lineage and cell migration studies in embryology. It is also a good marker for cell transplantation and nuclear transplantation experiments such a s fish cloning. Transgenic fish can also be engineered to detect environmental pollution, for example.

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Neon

A neon sign is a very simple device. It consists of a vacuum-tight glass tube, fitted at each end with an electrode. Inside the tube is a small amount of rare gas. Connected to the two electrodes is a source of high-voltage electrical power. When the current is turned on, the tube glows with a steady piercing light. The rare gases, neon, argon, helium, xenon and krypton, are ideally suited for use in signs. The two most common gases used in neon signs are neon and argon. While neon is very bright, argon's light is weak due to its low resistance. Neon gas gives off a red glow. This gas is normally contained in tubing that is clear in color, and when illuminated, projects the brightest red color. Almost everything else is filled with argon gas. When you see yellow, blue, green, white or any of several other shades, these tubes are filled with argon gas.