Colour management
Every colour calculation runs in physically-linear light, and the picture is developed into screen colours once, at the end.
Linear light
Mixing light, brightening a glow and blending two layers are all done in linear colour, the way real light adds up. Blending in the display-encoded colour a monitor shows instead is what makes bright edges look muddy and gradients band.
That final conversion to display colours is the display encode, and it happens once. Everything before it, lighting, layer blending, glows and volumes, stays in unbounded linear light, so highlights go far brighter than white without being clipped early.
The defaults need no attention. The settings below are for changing the look deliberately: a different film look, a wider colour space, or a true HDR signal to an HDR display.
Tone mapping
A scene can contain light far brighter than a screen can show. Tone mapping rolls those bright values down into a range the display can carry, instead of clipping everything brilliant to flat white. Pick the operator as the View Transform in the canvas settings.
ACES Filmic (default) is a punchy cinematic curve, and the cheapest. A safe everyday pick. Very saturated colours can shift hue slightly as they brighten.
ACES Fitted is a higher-fidelity version of the same look.
AgX is gentler on saturated colours and keeps hues honest as they get bright. Use it for stylised work, neon and fire, and switch to it when bright neon or fire shifts toward an odd hue under the default.
Reinhard is a simple, classic roll-off. Light and old-school.
Uncharted 2 is a classic game-style filmic curve.
Standard changes contrast minimally and stays close to the colours you authored.
Un-tone-mapped applies no roll-off at all. It is a passthrough, mostly for EXR export and debugging.
Working space
The working space is the space all colour maths happens in.
Linear sRGB (default) covers the colours a normal screen can show.
ACEScg is a much wider space used in film and VFX. Choose it for very saturated lights, for better colour blending under intense lighting, or to match a film pipeline.
Switching to ACEScg converts materials and colours into the wider space before lighting, then maps anything too saturated to display back down on the way out so it does not clip harshly. Neither step is managed by hand.
HDR output and display gamuts
The display gamut is the final target the picture is encoded for, meaning the range of colours and brightness sent to the screen or file.
sRGB is the default, the standard desktop and web target. Rec.709 is the same primaries with the broadcast 2.4-gamma transfer.
Display P3 and Rec.2020 for wider-gamut screens, giving richer reds and greens.
Rec.2100 PQ and Rec.2100 HLG for true HDR output. On a display that supports HDR, these send a real HDR signal and highlights shine far brighter than normal white.
Linear bypasses the display encode entirely, for floating-point HDR export.
Switching to an HDR gamut on a supported HDR monitor (macOS or Windows) reconfigures the live viewport without a restart.
HDR is honest only when the whole chain supports it: an HDR-capable display, and an HDR-capable file format on export. Exporting an HDR canvas to an 8-bit format like PNG falls back to standard sRGB tags and raises a warning, because an 8-bit file cannot carry HDR faithfully. Use EXR for true HDR stills. HDR video output is not built yet.
The canvas colour settings
All three live on the canvas: Working space, the space the colour maths happens in; View Transform, the tone mapping curve; Display gamut, the final colour and brightness target. Changing any of them updates the whole canvas live.
Converting one image, not the project
The settings above are project-wide. To move a single image between spaces, use the Color Space node: it takes a Source Space and a Target Space, each of which can be Working Space, sRGB, Linear sRGB or ACEScg, and converts between them. It also declares what it produced, so nodes downstream read the image in the space it is actually in rather than assuming linear. Reach for it when footage arrives already display-encoded, or when a texture has to leave in a specific space.
Screen and export match
The live viewport and exported files use the same colour maths, so a render matches the canvas. Export also tags each file, so PNG, TIFF, video and EXR carry the colour metadata other apps read. EXR is the exception: it is saved as raw linear light with no display encode, and film and compositing apps colour-manage it on the way in.