Skip to content
Free public beta until December 4, 2026: every course is open, no card needed. After that, the first chapter of each course stays free and full access is a one-time $39 ($19 for up to 100 founding members chosen for helpful feedback). Your progress is kept. How the beta works

Which color space do I need?

RGB, CMY/CMYK, HSV/HSL, YCbCr, or CIE Lab -- five ways to represent the same color, each built for a different job.

Reach for this whenever a task is easier in some OTHER representation of color than whatever an image arrived in -- ask what the task actually needs: device capture/display, printing, "pick out only the red pixels," video/JPEG bandwidth, or a distance that tracks how different two colors actually LOOK to a human.

How an image is captured and displayed

Term

RGB image

See section →
A color image storing three independent intensity values (red, green, blue) per pixel.

The default a camera sensor and a screen both work in natively -- start and end here unless another space solves a specific problem.

How an image gets printed

Term

CMY / CMYK

See section →
The subtractive ink color model -- cyan, magenta, yellow, plus a separate black channel extracted from what all three share.

Ink is subtractive, not additive, and RGB's own gamut doesn't survive the conversion untouched -- convert only at the point of printing.

Picking out "the red pixels", by eye-intuitive coordinates

Term

HSV

See section →
Hue, saturation, value -- color split into which hue, how vivid, and how bright the brightest channel reads.

Example

Selecting all the red pixels in a photo taken under warm indoor lighting, where raw R values alone shift with the light.

Hue/saturation/value -- thresholding a hue RANGE is far more robust to lighting changes than thresholding raw R, G, B separately.

Term

HSL

See section →
Hue, saturation, lightness -- the same hue/saturation idea as HSV, but brightness measured as the midpoint between the RGB extremes.

Same hue/saturation idea as HSV, with lightness defined as the midpoint between the RGB extremes instead of the brightest channel -- the choice behind most color-picker sliders.

Video and JPEG compression

Term

YCbCr

See section →
Luma (brightness-like) separated from two chroma (color-difference) channels, the basis of video and JPEG chroma subsampling.

Separates luma (which the eye resolves finely) from two chroma channels (which it doesn't) -- exactly what lets chroma subsampling cut data with little visible loss.

A perceptually meaningful color DISTANCE

See section →
A device-independent, perceptually uniform color space defined relative to a white point -- equal numeric distance tracks equal perceived difference.

The only space in this list where equal numeric distance tracks equal perceived difference -- reach for this specifically when comparing "how different do these two colors look," not just naming or thresholding one.

Graph settings

Calculator