Wedgwood Jasper : Color & Date Guide
Jasper Trials The result of several thousand individual experiments, over a period of years, was Jasper. The composition of Jasper was a closely guarded secret at the time, but is now known to have contained barium sulphate, resulting in a white stoneware body with a matte finish, which was easily tinted with the addition of metal oxides.

The bas-relief decoration was made separately in sprig moulds, and then applied to the surface of the piece.

The following chart is updated regularly, and has been compiled from my own research. Certain dates can be commented on with some degree of authority, however if a certain color is requested, that color can be "resurrected" for production use. There are always exceptions in regard to colour and date concerning Wedgwood Jasper.

(If you have further information or corrections, please contact me.)
BLACK DIP Black dip produced 1778-c.1826, 1844-1941, 1948-86 with prestige and special order items thereafter.
SOLID Solid Black in production 1778-c.1826, c.1866-1941, 1948-86, phased out by 1977 except for collectors items - for bas-relief work, and for ornamental pieces in the 20th century.  (Black Jasper and Basalt, although they are both dry-bodied ware, are two entirely different things.)
BLACK, BARBERINI DIP Solid Blue-Black pieces dipped in Black, made specifically for the Portland Vase, 1789-90.
BLUE, DARK (COBALT) DIP Dark Blue dip produced from 1777-c.1820, 1866-1941. Dark Blue or Cobalt Blue hues range from bright deep blue to dark navy blue. Some Dark Blue items are early solid Pale Blue items which were dipped in Dark Blue slip to save on costly cobalt oxide.
BLUE, MAZARINE DIP Mazarine Blue dip produced from 1777-c.1820.
BLUE, MIDNIGHT SOLID Pieces of this color were produced in 1999, as part of the modern "Interiors" line of vases, bowls etc. Colors in this line were also Primrose and Lilac, however, printed designs, and not bas-reliefs were featured on this ware.
BLUE, PALE DIP Pale Blue dip produced 1777-1826, 1841-1941, 1948-86, to Present.
SOLID Solid Blue produced 1775-c.1820, 1860-1941, 1948.
BLUE, PORTLAND SOLID Portland Blue first produced 1969. Introduced 1972, production was for a short period. Produced again in 1980.   Revived in 1992.
BLUE, ROYAL SOLID Royal Blue introduced 1953 (To celebrate the Coronation), produced for a short period, 1-3 years, discontinuation date unknown.)  Revived in 1977 for the Silver Jubilee.  Revived in 1980 for a full size 'Portland Vase' production, limited edition of fifty.
DIP Royal Blue dip produced in 1989 only.
BROWN, CHOCOLATE DIP Chocolate Brown dip produced for trials c.1777.5
SOLID Solid Chocolate Brown items produced 1779-c.1820.
Modern Chocolate Brown introduced in 2007 for the 'Jasper Elegance' range with White bas-reliefs.
BROWN, TAUPE SOLID Taupe introduced 1982.
BROWN, LIGHT TAUPE SOLID Light Taupe Brown introduced in 2006 for the 'Jasper Elegance' range with White bas-reliefs.
CRIMSON DIP Crimson dip production occured initially during the late 1800's, c.1880.1
Short production attempted again in 1910, with more general production from 1925-32, but was discontinued due to color bleeding. The color of Crimson dip varies from a scarlet-like shade, through to a dark burgundy hue due to the unstable nature of this colored slip.
WINE SOLID Wine (also incorrectly referred to as Crimson) introduced 2002, pieces seemingly made for a limited overseas market.
GREEN, CELADON SOLID Celadon dip produced only in 1879 for Boehm's bust of Gladstone.2
GREEN, DYSART (PEACH) SOLID Dysart dip produced only in 1882 for Buckminster Park work.2
GREEN, LIME SOLID Lime Green, date unknown, possibly c.1980's. Color developed for Barclay's Bank only.3
GREEN, SEA SOLID Sea Green (Eau de Nil/Water of the Nile), 1988. Color developed for Lloyd's of London only.3
GREEN, OLIVE DIP Olive dip produced c.1875 and earlier.4
Short production c.1910. Dark Olive Green produced more generally from 1920-30.
GREEN, SAGE DIP Sage Green dip produced 1777-1826, 1843-1941. Re-introduced after 1948 for special orders and trials only.
SOLID Solid Sage produced 1775-1820, 1860-1941, 1950-86.
GREEN, SPRUCE SOLID Spruce Green introduced 1997, produced until 1999.
GREEN, TEAL DIP Teal dip produced c.1890-c.1930. Dipped Teal items can be found in three shades; light, medium, and dark.
SOLID Solid Teal introduced 1984 (To celebrate 225 years of Wedgwood.) - produced until c.1989.
GREEN, TURQUOISE DIP Turquoise dip produced c.1875-c.1885.
SOLID "Dark Turquoise" introduced 2006.
GREY DIP 'Quaker' Grey dip produced in 1879 only.
SOLID Solid Grey produced 1777-c.1820. Produced again in c.1960 for trials only. Re-introduced 1991, discontinued to unpopularity.
LILAC DIP Lilac dip produced 1777-1820, 1860-c.1920.
SOLID Solid Lilac produced originally only for bas-relief work, 1777-c.1790. Limited quantities, 1959. Full production 1960-64. Re-introduced 1980-1984. Limited quantities, 1989, 1990, 1999.  Lilac hues range from pink-toned lilac, a peach-toned lilac, and through to a grey-toned lilac.
PINK SOLID Pink introduced 1982.
TERRACOTTA SOLID Solid Terracotta introduced for bas-relief work from 1775, with full production from 1957-1959. Limited quantities thereafter. At time of 1957 issue, the color looked a dark salmon pink hue with White or Black bas-relief work.
TURQUOISE, GREEN DIP Turquoise dip produced c.1875-c.1885.
TURQUOISE, DARK SOLID Dark Turquoise introduced in 2006 for the 'Jasper Elegance' range with White bas-reliefs.
YELLOW DIP Yellow dip produced from 1777-c.1820, 1869-1890.
SOLID Solid Yellow produced 1777-c.1820.
YELLOW, BUFF DIP Buff Yellow dip produced from c.1778, in small quantities.
SOLID Solid Buff Yellow produced 1929-1933 with Black bas-relief work.
YELLOW, CANE DIP Cane Yellow dip produced in 1805 only.
SOLID Solid Cane Yellow introduced 1998.
YELLOW, PRIMROSE SOLID Primrose Yellow produced 1976-1982, utilised for a small range of items including the 'Prunus' and 'Bamboo' wares, with White or Terracotta bas-relief.
WHITE SOLID Solid White produced 1774-c.1826, 1844-1941, 1946-1986. c.2000.
1 (Crimson) : Robin Reilly and other publications refer to Crimson production earlier than 1910. Pieces recorded with datemarks from 1898.
2 (Green, Celadon & Green, Dysart) : Colors noted in the book, Wedgwood: The New Illustrated Dictionary by Robin Reilly.
3 (Green, Lime & Green, Sea) : Different colored Jasper has been produced for certain organizations.
4 (Green, Olive) : The Wedgwood Handbook by Elizabeth Meteyard, refers to "Olive Green - light and very dark. These last are somewhat rare." This book was first published in 1875.
5 (Brown, Chocolate) : Color noted in the book, Wedgwood: The New Illustrated Dictionary by Robin Reilly. Brown pieces from this era have sometimes mistakenly been refered to as an early Taupe.