Colour management for photo editing and screen calibration
Colour management gives elementary OS a shared language between photographs, applications and monitors. It does not invent detail or make a poor panel accurate; it tells software how the values in a file relate to the colours a particular display should emit. That makes it essential for judging exposure, skin tones and edits, especially when an image will be viewed on phones, projectors and print.
A dependable workflow has three layers: preserve the profile attached to the source, convert deliberately into a working space, and use the right profile for each destination. elementary OS can support that workflow, but its desktop panel, GIMP, a browser and a printer may not consume colour information in exactly the same way. The guidance here focuses on standard dynamic-range photo work; HDR needs its own display, application and output checks.
What the colour stack controls
An ICC display profile maps encoded RGB values to a measured or characterised display. It describes elements such as the red, green and blue primaries, white point, luminance range and tone response. The operating system associates that profile with the correct screen, allowing applications to convert file colours into sensible values for that panel. Without this mapping, identical RGB numbers can produce visibly different colours on two monitors.
The stack must agree at several levels. The display server routes the image, the system colour service recognises displays and profiles, and the application converts between colour spaces. elementary OS builds on the wider Linux ecosystem, where ICC profiles and the LittleCMS colour engine are common, but particular releases may expose different controls. GIMP offers colour-managed editing, while a basic viewer or browser may handle only sRGB consistently.
Assigning a profile does not improve the panel itself, and a generic profile can hide rather than reveal display errors. A wide-gamut monitor without the correct profile may cause applications to clip saturated colours. HDR also changes the expected luminance and colour behaviour, so it should be disabled for a controlled SDR editing session unless the complete HDR workflow is understood and validated.
Configure the desktop display
Open Settings and select Displays, then look for Color, Color Profile or Color Management, depending on the elementary OS release. The profile chooser may sit within the Displays panel or appear as a separate panel. Release-specific differences in Switchboard are discussed through the elementary OS community site, which is useful for confirming menus before installing additional system packages.
Use the monitor’s native resolution, and return to 100 per cent scaling when checking individual pixels. Normal HiDPI scaling remains convenient for everyday work, but fractional scaling can make fine colour or sharpness judgements harder. During editing, disable Night Light, automatic dimming and other blue-light filters because they shift the white point. Adjust brightness through the monitor’s physical controls rather than an additional software filter.
Choose a profile that matches the exact display. A supplied manufacturer profile is appropriate only for the stated model and size; a profile from a similar 24-inch monitor is not a valid substitute. Generic sRGB is a safer starting point for an unidentified panel, but it does not prove that the monitor can actually reach the sRGB reference values. Restart an application if it fails to notice a newly assigned profile.
Build a repeatable photo workflow
JPEG and TIFF files may already contain an sRGB or Adobe RGB profile. Preserve that embedded information when opening and saving them. Camera RAW files work differently: raw converters apply a demosaicing process and develop the image in a working space rather than opening the RAW data as display-ready RGB. Converting it for a particular output does not mean every original file must be forced into the same space.
Choose a working space according to the source, editing operations and delivery target. Converting every file directly to sRGB can discard useful colour flexibility, while keeping a very wide space for a basic edit adds complexity without benefit. For websites and social platforms, an sRGB export is usually the common denominator. For printing, obtain the profile supplied by the output lab instead of assuming that sRGB will match its inks and paper.
These approaches solve different parts of colour management:
| Method | What it establishes | Equipment needed | Best suited to | Main limitation |
|---|---|---|---|---|
| Assigned display profile | A mapping between file values and the intended display characteristics | None | A panel known to match the selected profile | A borrowed or generic profile can create false confidence |
| Manufacturer profile | The vendor’s intended values for a particular model | None | An exact model with a reliable profile file | It may describe the nominal panel rather than the individual unit |
| Colorimeter calibration | Measurements from the actual red, green, blue and white channels | A compatible colorimeter | A repeatable reference for detailed editing | It must be repeated as the display and environment change |
| Visual brightness and contrast controls | Display output levels only | Monitor controls | Basic setup and convenience | It cannot characterise gamut, white point or gamma accurately |
Most editing setups combine an assigned profile with measurements from a colorimeter. Soft-proofing then simulates a second target profile inside GIMP, allowing clipping and gamut differences to be checked before export. The simulation still passes through the managed display, so inspect it at 100 per cent and keep proofing conditions stable. A soft proof cannot compensate for an inaccurately assigned monitor profile.
Calibrate with a measuring device
Visual adjustment can make a screen appear neutral, but it cannot produce a dependable description of the display. A colorimeter measures luminance and chromaticity, allowing calibration software to build an ICC profile for the individual panel. Hardware designed for ambient light, such as a colorimeter with a diffuse shroud, is more practical than a glossy-screen probe in a room with reflections.
Allow a new display to warm up for about 30 minutes. Use a stable white target such as D65, with luminance appropriate to the panel and room; roughly 100–120 cd/m² is common for SDR desktop editing, although OLED blacks and glossy reflections require different expectations. Calibration software based on ArgyllCMS or supplied by the device vendor can measure white point, gamma and primary targets. Avoid forcing impossible black levels or targeting Adobe RGB unless the display is designed for that gamut.
Lighting can change the result as much as the hardware. Sydney and Melbourne photographers often work in apartments or compact studios with large windows, where low winter sun and intense summer daylight create very different reflections. Close blinds, remove coloured objects near the screen and use consistent artificial lighting. For deeper coverage of white points, luminance and panel variation, display colour measurements provides useful technical context beyond a one-time factory preset.
Coordinate screens and software
Assign a separate profile to each physical display. A laptop screen and an external 4K monitor may have different gamuts, white points and luminance ranges even when they use the same resolution. Colour-managed applications can report the active profile, but some may cache it until they are reopened. Copying the laptop’s profile to an external monitor does not describe that monitor and will produce misleading previews.
Place the reference screen at a comfortable viewing angle and keep it away from strong coloured light. Glossy laptop panels and flat office monitors can change contrast according to viewing position. In a multi-screen setup, verify which output is active before judging an image. The browser may render an embedded profile correctly while an image viewer ignores it, so final visual checks should occur in an application known to honour the selected display profile.
Australian buyers often compare gaming and USB-C monitors sold by general electronics retailers such as JB Hi-Fi or Harvey Norman, along with second-hand marketplace listings. “Factory calibrated” can mean that each unit was adjusted, yet the vendor may still provide no ICC file. In Australian usage, a preview might be described as “keen” or “punchy”; neither description measures accuracy. When sending work to a Melbourne, Brisbane or regional print lab, request that lab’s ICC profile and confirm whether it expects embedded profiles in the supplied files.
Maintain an honest editing routine
Treat each calibration profile as a dated record rather than a permanent property of the monitor. Save the profile, calibration report, target settings, display model and serial number. Recalibrate after moving the screen, changing its lighting, replacing a connected computer or noticing unstable brightness. The useful interval depends on the panel and working conditions, so visible drift and failed checks are stronger triggers than a fixed calendar rule.
At the start of an editing session, confirm the active profile, disable colour-changing display effects and allow the monitor to stabilise. Inspect the image with any proofing profile enabled, then export for its actual destination. Keep the working master separate from the delivery copy, and document any conversion between sRGB, a wide-gamut space and a printer-specific profile.
Archive the relevant profiles with the project notes so that later corrections remain reproducible. The practical takeaway is to judge colour on a measured display under controlled light, recheck it when the setup changes, and never let a pleasant-looking preview substitute for a documented profile.
