Iron oxide red is a generic name of a
ferric oxide
Iron(III) oxide or ferric oxide is the inorganic compound with the formula Fe2O3. It is one of the three main oxides of iron, the other two being iron(II) oxide (FeO), which is rare; and iron(II,III) oxide (Fe3O4), which also occurs naturally a ...
pigment of the
red color. Multiple shades based on both
anhydrous
A substance is anhydrous if it contains no water. Many processes in chemistry can be impeded by the presence of water; therefore, it is important that water-free reagents and techniques are used. In practice, however, it is very difficult to achie ...
and its
hydrate
In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was understo ...
s were known to painters since
prehistory
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of ...
. The pigments were originally sourced from natural sources, since the 20th century they are mostly synthetic. These substances form one of the most commercially important groups of pigments. The names of the variants and sometimes reflect the location of a natural source, later transferred to the synthetic analog. Well-known examples include the Persian Gulf Oxide with 75% and 25%
silica
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one ...
,
Spanish red with 85% of oxide,
Tuscan red.
Properties
The anhydrous pigment has a dark purple-red or
maroon
Maroon ( US/ UK , Australia ) is a brownish crimson color that takes its name from the French word ''marron'', or chestnut. "Marron" is also one of the French translations for "brown".
According to multiple dictionaries, there are var ...
color, hydrates' colors vary from dull yellow (
yellow ochre) to warm red.
The iron oxide red is extremely stable: it is not affected by light and most chemicals (
soluble in hot concentrated
acid
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...
s); heat only affects the hydrated variants (the water is removed, and the color darkens).
Indian red
Indian red is a
pigment
A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compo ...
, a variety of
ocher
Ochre ( ; , ), or ocher in American English, is a natural clay earth pigment, a mixture of ferric oxide and varying amounts of clay and sand. It ranges in colour from yellow to deep orange or brown. It is also the name of the colours produced ...
, which gets its colour from
ferric oxide
Iron(III) oxide or ferric oxide is the inorganic compound with the formula Fe2O3. It is one of the three main oxides of iron, the other two being iron(II) oxide (FeO), which is rare; and iron(II,III) oxide (Fe3O4), which also occurs naturally a ...
, used to be sourced in
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
, now made artificially. Other shades of iron oxides include
Venetian Red,
English Red, and
Kobe
Kobe ( , ; officially , ) is the capital city of Hyōgo Prefecture Japan. With a population around 1.5 million, Kobe is Japan's seventh-largest city and the third-largest port city after Tokyo and Yokohama. It is located in Kansai region, whic ...
, all shown below.
Chestnut
The chestnuts are the deciduous trees and shrubs in the genus ''Castanea'', in the beech family Fagaceae. They are native to temperate regions of the Northern Hemisphere.
The name also refers to the edible nuts they produce.
The unrelat ...
is a colour similar to but separate and distinct from Indian red.
Etymology
The name ''Indian red'' derives from the red
laterite
Laterite is both a soil and a rock type rich in iron and aluminium and is commonly considered to have formed in hot and wet tropical areas. Nearly all laterites are of rusty-red coloration, because of high iron oxide content. They develop by ...
soil found in
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
, which is composed of naturally occurring
iron oxide
Iron oxides are chemical compounds composed of iron and oxygen. Several iron oxides are recognized. All are black magnetic solids. Often they are non-stoichiometric. Oxyhydroxides are a related class of compounds, perhaps the best known of whic ...
s. The first recorded use of ''Indian red'' as a color term in
English
English usually refers to:
* English language
* English people
English may also refer to:
Peoples, culture, and language
* ''English'', an adjective for something of, from, or related to England
** English national ide ...
was in 1672.
Deep Indian red
Deep Indian red is the colour originally called ''Indian red'' from its formulation in 1903 until 1999, but now called ''chestnut'', in
Crayola crayon
A crayon (or wax pastel) is a stick of pigmented wax used for writing or drawing. Wax crayons differ from pastels, in which the pigment is mixed with a dry binder such as gum arabic, and from oil pastels, where the binder is a mixture of wax an ...
s. This colour was also produced in a special limited edition in which it was called Vermont maple syrup.
At the request of educators worried that children (mistakenly; see
Etymology
Etymology ()The New Oxford Dictionary of English (1998) – p. 633 "Etymology /ˌɛtɪˈmɒlədʒi/ the study of the class in words and the way their meanings have changed throughout time". is the study of the history of the Phonological chan ...
) believed the name represented the
skin color of
Native Americans, Crayola changed the name of their crayon color ''Indian Red'' to ''Chestnut'' in 1999.
Indian red in culture
;Railroads/Railways
* The
Talyllyn Railway
The Talyllyn Railway ( cy, Rheilffordd Talyllyn) is a narrow gauge preserved railway in Wales running for from Tywyn on the Mid-Wales coast to Nant Gwernol near the village of Abergynolwyn. The line was opened in 1865Drummond 2015, page 17 ...
painted their locomotives ''Talyllyn'' and ''Dolgoch'' Indian Red in honour of the 150th anniversary of the line in 2015.

* The
Furness Railway in the UK used ''Indian Red'' for its locomotive livery.
* The
Department of Railways New South Wales,
Public Transport Commission
The Public Transport Commission (PTC) was an agency of the Government of New South Wales responsible for the provision of rail, bus and ferry services in New South Wales, Australia from October 1972 until June 1980.
Upon dissolution, responsib ...
and
the State Rail Authority painted their diesel locos and passengers cars in Indian red.
Venetian red
At right is displayed the colour Venetian red.
''Venetian red'' is a light and warm (somewhat unsaturated) pigment that is a darker shade of
scarlet, derived from nearly pure
ferric oxide
Iron(III) oxide or ferric oxide is the inorganic compound with the formula Fe2O3. It is one of the three main oxides of iron, the other two being iron(II) oxide (FeO), which is rare; and iron(II,III) oxide (Fe3O4), which also occurs naturally a ...
(Fe
2O
3) of the
hematite
Hematite (), also spelled as haematite, is a common iron oxide compound with the formula, Fe2O3 and is widely found in rocks and soils. Hematite crystals belong to the rhombohedral lattice system which is designated the alpha polymorph of . ...
type. Modern versions are frequently made with synthetic red iron oxide.
The first recorded use of ''Venetian red'' as a colour name in English was in 1753.
English red
At right is displayed the colour English red.
This ''red'' is a tone of Indian red, made like Indian red with pigment made from iron oxide.
The first recorded use of ''English red'' as a colour name in
English
English usually refers to:
* English language
* English people
English may also refer to:
Peoples, culture, and language
* ''English'', an adjective for something of, from, or related to England
** English national ide ...
was in the 1700s (exact year uncertain). In the ''
Encyclopédie'' of
Denis Diderot
Denis Diderot (; ; 5 October 171331 July 1784) was a French philosopher, art critic, and writer, best known for serving as co-founder, chief editor, and contributor to the ''Encyclopédie'' along with Jean le Rond d'Alembert. He was a promine ...
in 1765, alternate names for Indian red included "what one also calls, however improperly, English Red."
Kobe
At right is displayed colour kobe.
The colour kobe is a dark tone of Indian red, made like Indian red from iron oxide pigment.
The first recorded use of Kobe as a colour name in
English
English usually refers to:
* English language
* English people
English may also refer to:
Peoples, culture, and language
* ''English'', an adjective for something of, from, or related to England
** English national ide ...
was in 1924.
The
normalized colour coordinates for Kobe are identical to
sienna, first recorded as a colour name in English in 1760.
[Maerz and Paul ''A Dictionary of Color'' New York:1930 McGraw-Hill p. 204; Color Sample of Sienna: p. 37 Plate 7 Color Sample E12]
See also
*
Chestnut (color)
Chestnut or castaneous is a colour, a medium reddish shade of brown (displayed right), and is named after the nut of the chestnut tree. An alternate name for the colour is badious.
Indian red is a similar but separate and distinct colour fro ...
*
List of colors
References
Sources
*
*
{{Color topics
Iron oxide pigments
Shades of red
Shades of brown
Indian culture