Short answer
Most often because the screen was much brighter than paper can be and the print is being looked at in warm or dim light — two viewing problems, not printing ones. After that come a screen that exaggerates colour, a conversion made with a profile nobody chose, and proofs that are deliberately simulating a duller production paper. Match the screen to a sheet of paper and look at the print in daylight before touching the file.
1. The screen is far brighter than paper in the room
Test: Hold a blank sheet of the print's paper beside the screen while it shows a white page. If the screen glows against the paper, turn its brightness down until the two whites are similar, then look at the file again.
An image edited on a screen several times brighter than paper is made too dark without anyone noticing. The print is accurate; the screen was flattering.
2. The print is being judged under warm or dim light
Test: Take the print to a window in daylight, out of direct sun, and compare again. If the yellow cast and the dullness mostly disappear, the lamp was the difference.
Print is prepared to be viewed in a daylight-like white light at a set level. A warm lamp tints the paper and every colour on it, while the screen keeps its own cooler white.
3. The screen is showing more saturation than the file holds
Test: Open the file in a colour-managed viewer with the screen in its standard or sRGB mode, or on a second device. If colours calm down, the first view was exaggerated.
Wide-gamut panels, vivid modes and software that ignores colour profiles all display ordinary files louder than they are.
4. The file was converted with a profile nobody chose
Test: Ask the printer which profile or printing condition they converted to, then soft-proof the file with it. If the soft proof looks like the print, the conversion explains the difference.
An RGB file is converted by whatever default the printer's software holds. A default meant for another paper shifts tone and colour throughout.
5. A contract proof is simulating the production paper
Test: Look at an unprinted margin of the proof beside its trimmed edge or its back. If the 'white' area carries a faint printed tint, the proof is reproducing a darker or creamier production stock.
A contract proof shows the press result, paper colour included, so its whites and blacks are meant to be weaker than the screen's.
6. Some colours are outside what the process can print
Test: Run the colours that differ most through the CMYK gamut check. Colours flagged outside will change whatever else is put right.
Saturated screen colours beyond the ink gamut are moved to the nearest printable colour, which is duller and sometimes a different hue.
Causes are ordered by how often Colourwise expects each to be the explanation — an editorial judgement, so test them all.
This page is for prints that are clean but different — darker, yellower, or with a white that is not white. Dirty, brownish or clogged colour is a separate problem with separate causes. Work through the cheap tests in order, because each one removes a suspect without touching the file. First hold a blank sheet of the paper beside the screen: if the screen's white glows by comparison, the screen is the unreliable witness. Next take the print to a window: if it improves, the room light was. Only when the print still disagrees with a dimmed screen in daylight is it worth asking how the file was converted, and whether the thing in your hand is a proof that was meant to look like a particular press and paper.
Paper has no light of its own. Under 500 lux, the level the printing standards use for everyday appraisal, the white of a coated sheet has a luminance of about 140 candelas per square metre, and at half that light about 70. Photo labs that publish screen settings ask for about 120, or 120 to 160, for the same reason. Screens can be set far brighter than that. An image edited until it looks right on such a screen has been made too dark for paper: mid-tones and shadows that glowed on the display sink on the sheet. The table on this page gives the luminance of paper white at several light levels, as a target to set a screen against; the cruder test of matching a white window to a sheet of paper gets close enough.
Screens are built to a bluish daylight white. Print is prepared for a slightly warmer daylight, and is then usually looked at under lamps that are warmer again. Side by side, the eye settles on the brighter screen as its white, and the paper looks yellow and dull against it; alone under the lamp, the same print looks fine. That is a mismatch of viewing conditions, not of colour, and editing the file to cancel it produces prints that are too blue everywhere else. Compare in daylight from a window, out of direct sun, or under a viewing light made for the purpose, and let the eyes rest on one of the two at a time instead of flicking between them.
A contract proof is not trying to look like the screen. It is made to show what a named press and paper will produce, so it reproduces that paper's colour in the unprinted areas and that press's weaker black in the shadows; a faint tint in its whites is the proof working. Its accuracy is checked by measurement against published tolerances, whereas an uncalibrated screen has been checked against nothing. Where the two disagree, the proof is the better evidence of the final result. To make a screen agree with it, soft-proof with the same printing condition and paper simulation switched on — and expect the first sight of that preview to look flat, because it is the honest one.
| Light falling on the sheet | Perfect white surface | Premium coated (FOGRA51) | Wood-free uncoated (FOGRA52) | Newsprint (IFRA26) |
|---|---|---|---|---|
| 125 lux | 40 | 35 | 33 | 26 |
| 250 lux | 80 | 70 | 67 | 53 |
| 500 lux | 159 | 139 | 134 | 106 |
| 1,000 lux | 318 | 279 | 268 | 211 |
| 2,000 lux | 637 | 558 | 535 | 423 |
Why: The files were edited on a screen set far brighter than paper in the room.
Fix: Dim the screen to match a sheet of paper, re-edit one page to look right, and test with a single print.
Why: The proof is reproducing the colour of the production paper, as a contract proof should.
Fix: Judge it against the production stock, not against the screen's white or the proofing paper's own.
Why: The yellow was the room light; the file was right and has now been pushed the other way.
Fix: Undo the correction and judge prints in daylight or under a D50 viewing light.
Each statement is labelled by kind — established fact, a standard’s requirement, observed market data, a convention, or Colourwise’s own interpretation or analysis — with the strength of the evidence behind it.
Colourwise analysisModerate evidence
Computed from the published paper white of premium coated offset paper (L* 95), the sheet has a luminance of about 139 cd/m² under 500 lux and about 70 cd/m² under 250 lux; a perfectly white surface under 500 lux would be about 159 cd/m².
Based on: Luminance of an ideal matt surface, L = E × ρ / π, with ρ the luminance factor computed from the FOGRA51 paper white. The perfect-white figure agrees with a photo printer's statement that 160 cd/m² corresponds to 500 lux.
Caveat: Assumes a perfectly matt surface; glossy paper and uneven lighting change the figure.
Source: FOGRA51 characterization data (premium coated offset, ISO 12647-2:2013); CEWE frequently asked questions (image correction, screen settings, sharpening)
FactModerate evidence
One professional photo lab recommends calibrating an editing screen to 6500 K, gamma 2.2 and 120 cd/m², keeping brightness low because prints do not emit light; a large consumer photo printer recommends about 120 to 160 cd/m² depending on the room light.
Caveat: Two companies' own recommendations to their customers, not a standard.
Source: Monitor Calibration; CEWE frequently asked questions (image correction, screen settings, sharpening)
StandardModerate evidence
As summarised by a viewing-booth manufacturer, ISO 3664 bases print viewing on CIE illuminant D50, at 2,000 lux for critical comparison and 500 lux for practical appraisal.
Caveat: From a manufacturer's summary; the standard's text was not read.
Source: New edition of ISO 3664:2025. What has changed?; ISO 3664:2025 Graphic technology and photography — Viewing conditions
StandardStrong evidence
ISO 12647-7:2016 requires a contract proof's substrate to match the production substrate within 3.0 ΔE00 and its process solids to fall within 3.0 ΔE00 of their aims, so a proof's paper colour and ink strength are deliberate and verified.
Source: ISO 12647-7:2016 … — Part 7: Proofing processes working directly from digital data
Reviewed 1 October 2026. Colourwise summarises its sources in its own words and does not reproduce standards text or proprietary colour data. Spotted an error? Tell us.