Purple in the context of "CMYK color model"

Tyrian purple (Ancient Greek: πορφύρα porphúra; Latin: purpura), also known as royal purple, imperial purple, imperial dye, or simply tyrian, is a reddish-purple natural dye. The name Tyrian refers to the city of Tyre in ancient Phoenicia (modern-day Lebanon). It is secreted by several species of predatory sea snails in the family Muricidae, rock snails originally known by the name Murex (Bolinus brandaris, Hexaplex trunculus and Stramonita haemastoma). In ancient times, extracting this dye involved tens of thousands of snails and substantial labour, and as a result, the dye was highly valued. The coloured compound is 6,6'-dibromoindigo.

Porphyry (/ˈpɔːrfəri/ POR-fə-ree) is any of various granites or igneous rocks with coarse-grained crystals such as feldspar or quartz dispersed in a fine-grained silicate-rich, generally aphanitic matrix or groundmass. In its non-geologic, traditional use, the term porphyry usually refers to the purple-red form of this stone, valued for its appearance, but other colours of decorative porphyry are also used such as "green", "black" and "grey".

The term porphyry is from the Ancient Greek πορφύρα (porphyra), meaning "purple". Purple was the colour of royalty, and the Roman "imperial porphyry" was a deep purple igneous rock with large crystals of plagioclase. Some authors claimed the rock was the hardest known in antiquity. Thus porphyry was prized for monuments and building projects in Imperial Rome and thereafter.

Crimson is a rich, deep red color, inclining to purple.It originally meant the color of the kermes dye produced from a scale insect, Kermes vermilio, but the name is now sometimes also used as a generic term for slightly bluish-red colors that are between red and rose. It is the national color of Nepal.

The Boring Billion, otherwise known as the Mid Proterozoic and Earth's Middle Ages, is an informal geological time period between 1.8 and 0.8 billion years ago (Ga) during the middle Proterozoic eon spanning from the Statherian to the Tonian periods, characterized by more or less tectonic stability, climatic stasis and slow biological evolution. Although it is bordered by two different oxygenation events (the Great Oxygenation Event and Neoproterozoic Oxygenation Event) and two global glacial events (the Huronian and Cryogenian glaciations), the Boring Billion period itself actually had very low oxygen levels and no geological evidence of glaciations.

The oceans during the Boring Billion may have been oxygen-poor, nutrient-poor and sulfidic (euxinia), populated by mainly anoxygenic purple bacteria, a type of bacteriochlorophyll-based photosynthetic bacteria which uses hydrogen sulfide (H₂S) for carbon fixation instead of water and produces sulfur as a byproduct instead of oxygen. This is known as a Canfield ocean, and such composition may have caused the oceans to be colored black-and-milky-turquoise instead of blue or green as later. (By contrast, during the much earlier Purple Earth phase during the Archean, photosynthesis was performed mostly by archaeal colonies using retinal-based proton pumps that absorb green light, and the oceans would be magenta-purple.)

Violet is the color of light at the short wavelength end of the visible spectrum. It is one of the seven colors that Isaac Newton labeled when dividing the spectrum of visible light in 1672. Violet light has a wavelength between approximately 380 and 450 nanometers. The color's name is derived from the Viola genus of flowers.

In the RGB color model used in computer and television screens, violet is produced by mixing red and blue light, with more blue than red. In the RYB color model historically used by painters, violet is created with a combination of red and blue pigments and is located between blue and purple on the color wheel. In the CMYK color model used in printing, violet is created with a combination of magenta and cyan pigments, with more magenta than cyan. On the RGB/CMY(K) color wheel, violet is located between blue and magenta.

Magenta is a purplish red color. On color wheels of the RGB and CMYK color models, it is located directly midway between blue and red. It is one of the 4 colors of substractive ink used in color printing by most color printers, also known as CMYK along with yellow, cyan, and black to make all the other colors and hues. The tone of magenta used in printing, printer's magenta, is redder than the magenta of the RGB (additive) model, the former being closer to rose.

Magenta took its name from an aniline dye made and patented in 1859 by the French chemist François-Emmanuel Verguin, who originally called it fuchsine. It was renamed to celebrate the French-Sardinian victory under French Emperor Napoleon III at the Battle of Magenta against the larger army of the Austrian Empire on 4 June 1859 near the Italian town of Magenta, at the time in Austria. This battle was decisive in liberating Italy from Austrian domination.

Kaposi's sarcoma (KS) is a type of cancer that can form masses on the skin, in lymph nodes, in the mouth, or in other organs. The skin lesions are usually painless, purple, and may be flat or raised. Lesions can occur singly, multiply in a limited area, or may be widespread. Depending on the sub-type of disease and level of immune suppression, KS may worsen either gradually or quickly. Except for classic KS where there is generally no immune suppression, KS is caused by a combination of immune suppression (such as HIV/AIDS) and infection by Human herpesvirus 8 (HHV8 – also called KS-associated herpesvirus (KSHV)).

Classic, endemic, immunosuppression therapy-related (also known as iatrogenic), and epidemic (also known as AIDS-related) sub-types are all described. Classic KS tends to affect older men in regions where KSHV is highly prevalent (Mediterranean, Eastern Europe, Middle East), is usually slow-growing, and most often affects only the legs. Endemic KS is most common in Sub-Saharan Africa and is more aggressive in children, while older adults present similarly to classic KS. Immunosuppression therapy-related KS generally occurs in people following organ transplantation and mostly affects the skin. Epidemic KS occurs in people with AIDS and many parts of the body can be affected. KS is diagnosed by tissue biopsy, while the extent of disease may be determined by medical imaging.

Resazurin (7-Hydroxy-3H-phenoxazin-3-one 10-oxide) is a phenoxazine dye that is weakly fluorescent, nontoxic, cell-permeable, and redox‐sensitive. Resazurin has a blue to purple color above pH 6.5 and an orange color below pH 3.8. It is used in microbiological, cellular, and enzymatic assays because it can be irreversibly reduced to the pink-colored and highly fluorescent resorufin (7-Hydroxy-3H-phenoxazin-3-one). At circum-neutral pH, resorufin can be detected by visual observation of its pink color or by fluorimetry, with an excitation maximum at 530-570 nm and an emission maximum at 580-590 nm.

When a solution containing resorufin is submitted to reducing conditions (E_h < -110 mV), almost all resorufin is reversibly reduced to the translucid non-fluorescent dihydroresorufin (also known as hydroresorufin) and the solution becomes translucid (the redox potential of the resorufin/dihydroresorufin pair is -51 mV vs. standard hydrogen electrode at pH 7.0). When the E_h of this same solution is increased, dihydroresorufin is oxidized back to resorufin, and this reversible reaction can be used to monitor if the redox potential of a culture medium remains at a sufficiently low level for anaerobic organisms.

Hazarajat (Dari: هزاره‌جات), also known as Hazaristan (Dari: هزارستان), is a mostly mountainous region in the central highlands of Afghanistan, among the Kuh-e Baba mountains in the western extremities of the Hindu Kush. It is the homeland of the Hazara people, who make up the majority of its population. Hazarajat denotes an ethnic and religious zone.

Hazarajat is primarily made up of the provinces of Bamyan, Daikundi, Ghazni, large parts of Ghor, and Maidan Wardak, and small parts of Sar-e-Pol, Balkh, Samangan, Uruzgan, and Parwan. The most populous towns in Hazarajat are Bamyan, Yakawlang (Bamyan), Nili (Daikundi), Lal wa Sarjangal (Ghor), Sang-e-Masha (Ghazni), Gizab (Daikundi) and Behsud (Maidan Wardak). The Kabul, Arghandab, Helmand, Farah, Hari, Murghab, Balkh, and Kunduz rivers originate from Hazarajat.