Color matching is complicated by the fact that all early
paints were made by hand. Each batch of paint, made by painters
using books of paint "recipes" or using their own
experience and instincts, might well have slight variations
in color — a little darker or lighter, a little bluer
and so on.
The earliest known book of paint formulations by an American
painter is the 1812 guide by Hezekiah Reynolds. It gives instructions
for the relative quantities of tinting pigments to be added
to a base, but even with proportions held constant, the amount
of mixing, or dispersion, varied from workman to workman and
resulted in color variations.
Knowing all of the facts about early paints can aid in microscopic
paint study. For example, finding very finely and evenly ground
pigments, equally dispersed throughout the ground or vehicle,
is an immediate clue that the paint was not made by hand but,
rather, in a factory.
By the first decades of the 19th century more synthetic pigments
were available — chrome yellow, chrome green, and shades
of red. Discoveries of light, bright, clear colors in the
plaster and mosaic decoration of dwellings at Pompeii caught
the fancy of many Americans and came together with the technology
of paint to make for a new palette of choice, with more delicacy
than many of the somewhat greyeddown colors of the 18th century.
Of course, the blues which could be produced with Prussian
blue in the 18th and 19th centuries were originally often
strong in hue. That pigment — as were a number of others
— is fugitive, that is, it faded fairly quickly and
thus softened in appearance. It should be remembered that
high style houses from the mid-17th to late 19th centuries
often had wallpaper rather than paint on the walls of the
important rooms and hallways.