The wheel above is one color space. There are dozens more.
Everything on this site so far has used HSL — hue, saturation, lightness. That's a fine model for picking a color, but it says nothing about which physical reds, greens, and blues those numbers actually produce on a screen, a print, or a movie theater's projector. That's what a color space defines — and mixing them up is where most real-world color problems come from.
Standardized by HP and Microsoft in 1996. Fixed red, green, and blue primaries, a D65 white point, and a gamma curve that averages out to about 2.2. It's the assumed default for the web, most consumer monitors, and most photos straight out of a camera unless you deliberately choose otherwise.
The safe default for anything web-facing — if you don't know what space an image is in, it's probably this one.
Same D65 white point and similar gamma to sRGB, but different primaries that reach noticeably further into cyans and greens — colors a printer can reproduce that sRGB simply can't describe.
Photography and print-prep workflows, where that extra green-cyan range survives into the final printed piece.
DCI-P3 is the digital cinema projection standard. Display P3 is Apple's consumer adaptation of it — same wide primaries, but swapped to a D65 white point and an sRGB-style gamma so it behaves on a normal display instead of a theater projector.
The default wide-gamut space on iPhones, iPads, and Macs — increasingly what "wide gamut" means for a phone screen.
The ITU-R standard for HD video. Its red, green, and blue primaries are essentially identical to sRGB's — but its transfer function (the gamma-like curve, defined separately for camera capture and for display) is not the same curve as sRGB's, even though both are commonly rounded to "gamma 2.2" in casual conversation. Treating the two as interchangeable is a common source of footage that looks slightly wrong.
Broadcast and HD video delivery — the space most footage is graded for unless a project specifically targets UHD/HDR.
The primaries move much further out toward the edges of human vision than Rec. 709's, covering colors no consumer display from a decade ago could show at all. Built alongside the 4K/8K UHD broadcast standard.
UHD and HDR delivery — most real-world Rec. 2020 displays still can't reach every corner of the space it defines.
Cyan, magenta, yellow, and black ink absorbing light off a physical page — the subtractive process described on the Light vs. Material page. Unlike every space above, "CMYK" isn't one fixed gamut: a specific printer, ink set, and paper combination is what actually defines it, described by an ICC profile (common ones include U.S. Web Coated SWOP or GRACoL). Generally narrower than sRGB in vivid blues and greens, but some profiles exceed it in certain cyans.
Anything physically printed. Soft-proofing against the actual target ICC profile is the only reliable way to know how a color will really come out.
Why gamma exists at all
Human vision is far more sensitive to small changes in dark tones than in bright ones. Store brightness values on a straight 0–255 linear scale and you'd waste most of that range on highlight detail no eye can tell apart, while shadows band and posterize from too few steps to work with.
Gamma encoding compresses values non-linearly before storing them, roughly matching how the eye actually perceives brightness, so the same 8 bits per channel look smooth throughout the whole tonal range instead of just at the top. "Gamma 2.2" describes the shape of that curve — a straight power function is the simplification; sRGB's actual curve is a hybrid, linear near black and power-like everywhere else, and Rec. 709's camera-side curve is a third shape again, similar in effect but not identical in the numbers.
Log encoding — capture flat, grade later
Cinema cameras capture a far greater dynamic range than gamma encoding was designed to store efficiently, so they record in a log curve instead (Sony's S-Log, ARRI's LogC, Panasonic's V-Log, and others each vendor-specific). Log footage deliberately looks flat, gray, and desaturated straight off the camera — that's the sensor's full range compressed into the file without clipping the brightest highlights or crushing the darkest shadows.
That flat image isn't the final look — it's raw material. A colorist applies a transform (a LUT, or a manual grade) to map that log data back to something that reads correctly on a normal display. This is exactly the raw state footage is in before the White Balance → Exposure node pass covered in the photography course's DaVinci Resolve topic.
DaVinci Wide Gamut — one space to grade them all in
A real project rarely uses one camera. Mix an ARRI shooting LogC with a Sony shooting S-Log3 and a RED shooting Log3G10, and each clip's raw color data means something different — grading them side by side in their native camera spaces would mean every color tool behaves inconsistently from clip to clip.
DaVinci Wide Gamut (paired with the DaVinci Intermediate transfer function) is Blackmagic's answer: a single wide color space every camera's footage gets converted into before grading starts, so the same node, the same wheel, the same power window behaves identically no matter which camera the clip came from. It's Blackmagic's own version of a problem the wider industry also solves with ACES (the Academy Color Encoding System) — a shared, camera-independent working space, with defined transforms in from each camera format and back out to whatever the final delivery space is (Rec. 709, P3, Rec. 2020, print).