How accurate are colorized photos?

Why a black-and-white photo cannot show its color

A black-and-white photo recorded brightness only. Each point in the picture became one shade of gray, and many different colors land on the same shade.

Light adds a second ambiguity. A white shirt in shade and a gray shirt in sun can come out as the same mid-gray, so a gray tone mixes the color of the object with the light that fell on it.

Old film adds a third. Early emulsions barely registered red, so red lips could come out nearly black and blue eyes nearly white. Film sensitive to every color arrived in the early 1900s but became common only in the 1920s. A dark dress in an older portrait may have been red, and a pale eye may have been blue.

How do they know what color to make old photos?

They infer it. Whoever colorizes a photograph, a person or a program, works out what each area shows and gives it the color such things usually have.

A careful human colorist adds research: uniform regulations, catalogs, surviving objects, period color photographs, notes on the back of the print. Where the research runs out, the colorist picks a plausible color.

AI colorization replaces the research with pattern. Many systems learn from huge numbers of color photographs, often by removing the color and training the system to put it back, until they have learned which colors tend to go with which shapes, textures and settings. A model sees the photograph, not the archive: it does not look up the regiment, the year or the family. The same holds for Epoha: the color it gives a black-and-white photo is the model’s inference.

So every color in a colorized photograph falls into one of three groups. Documented: a source outside the photo says so. Inferred: it follows a strong pattern, such as skin or sky. Guessed: nothing decides it. The rest of this page uses those three words.

Are colorized photos accurate? It depends on the color

Broad colors are usually right, and specific colors are often wrong. The more a color follows a pattern, the safer the guess.

Skin, sky, foliage, water, wood, soil, brick and stone follow strong patterns, so a colorizer usually lands near the real hue. Even then, accurate means believable. Nobody can read a particular person’s complexion or the exact green of a July lawn from a gray print.

Anything dyed or painted by choice follows no pattern. A dress could have been almost any color, and the safe guess is an ordinary one, so colorized scenes tend to look more ordinary than the real ones did. Real colors can surprise: the Golden Gate Bridge is painted International Orange, and a gray photograph gives no hint of it.

How do historians check the color of an old photograph?

They look for evidence outside the photograph. A gray print cannot confirm its own colors, but other records often can.

Written descriptions come first: uniform regulations, manufacturers’ color charts, catalogs, letters and diaries. Surviving objects come next. A garment, a flag, a vehicle or a painted room in a museum or archive can be examined directly, though dyes fade and paint gets redone.

Color photographs of the same period are the best check, and early processes such as the autochrome mean they exist for more scenes than you might expect. Hand-colored prints and postcards are weak evidence, because a colorist usually chose those colors too.

Each check settles one color, so historians verify the colors that matter: a uniform, a flag, a ribbon. Our military photo guide goes through that list.

When were photos first colorized?

Almost from the beginning of photography. People colored photographs by hand long before any process recorded color.

Some daguerreotypes carry dry pigment applied by hand, and from the 1850s to the early 1900s hand-tinting was used mostly on portraits, in translucent oils, dyes or watercolors. Manuals of the time gave stock mixtures for skin, hair and drapery. Unless a customer said what the colors were, the tint shows what the colorist chose, the same job a modern colorizer does with software.

Processes that recorded color came later: a three-filter demonstration in 1861, autochrome plates in 1907 and Kodachrome film in 1935. A photograph whose color was recorded is a color photograph. One whose color was added afterward, by hand or by software, is a colored photograph, and a colorized photo belongs in that group. If you own a hand-tinted print, our guide to hand-tinted photos explains how to treat it.

Colorized vs original: which one is the record?

The original is the record. A colorized photo is an interpretation built on it, so the black-and-white scan stays the document and the color version is a way of looking at it. Keep both. Epoha returns every black-and-white or sepia photo in color, with no option to keep it gray, so your original scan is the black-and-white copy to hold on to.

Our restoration series works this way, and the Lincoln portrait above comes from it. Each story starts from a black-and-white original in a public archive, links to its catalog record and lets you hold the photograph to see the original in place of the color result. The color in every story is inferred from the gray original: in the first-flight photograph, for example, the sky and sand follow patterns and the shade of the man’s jacket does not.

How to label a colorized photo when you share it

Say that it is colorized, say what it was made from, and say how the colors were chosen. Put that within reach of the image, not on another page.

A caption that does the job in two lines: “Colorized from a black-and-white original ([photographer or collection], [year]). Colors inferred from the gray photograph.” If you checked a color against a source, add it: “Uniform color checked against [source].”

A reader who sees only the colorized version cannot tell which colors were checked. Credit the original photographer and archive, give the catalog number if there is one, and link to the black-and-white scan.