Color Picker#

View ▸ Color Picker (Shift + Cmd + K) opens a small floating panel in the manner of Digital Color Meter. Move the cursor over the page and it reports the color of whatever is drawn underneath, not as a screen sample but as the values written in the PDF itself:

DeviceCMYK                C 0%  M 100%  Y 100%  K 0%
DeviceGray                Gray 0%
Separation "DIC 161s*"    Tint 50%   (alt DeviceCMYK C 0%  M 32%  Y 50%  K 0%)
DeviceRGB                 R 0.000  G 0.400  B 1.000

Galley reads these from the page’s content stream, so a DeviceRGB black and a DeviceGray black are told apart, a rich black shows all four plates, and a spot color keeps its name. This is the question a screen sample cannot answer: not “what does this look like”, but “what did the PDF ask for”.

You can also open the panel by right-clicking the page and choosing Color Picker; it then reads the point you clicked straight away. While the panel is open the cursor is a crosshair. Esc or the menu item closes it.

Reading the panel#

From top to bottom:

• A magnifier showing the 24 pt square around the cursor, and a swatch of the color.
• The component values, one per line. CMYK, Gray and spot tints are given in percent; RGB components from 0 to 1, with a second line in 0–255.
• ≈ sRGB #RRGGBB — the color converted for display. It is an approximation, and the only value in the panel that is.
• The color space, what was hit, and any transparency: DeviceCMYK · Text "あ", Separation "DIC 161s*" · Fill, DeviceRGB · Stroke 1.99 pt · α 0.50 · Multiply.
• Notes, when there is something to say: the alternate color of a Separation, the stroke color of outlined text, invisible text (Tr 3), a Type 3 font, a stencil mask.
• The position: page label, physical page number when the two differ, and the point in page coordinates, e.g. p. iv (#4) (72.0, 640.5) pt.

Over blank paper the panel says No ink.

Exact and sampled values#

Text, fills and strokes are reported exactly, from the operators that drew them, together with constant alpha and blend mode. Strokes also report their line width; very thin fills such as a 0.4 pt rule are hit with a 2-pixel tolerance, so you do not have to land on them precisely.

Images, shadings and colored patterns have no single color in the content stream. For those, Galley waits until the cursor rests, rasterizes the spot and reports what it finds, marked (sampled). A CMYK image is sampled in a CMYK context, so its values round-trip rather than passing through RGB.

Display: other color spaces#

The Display popup re-expresses the reading the way Digital Color Meter’s “Display in …” menu does:

Anything other than Native Values is a conversion, and the panel says so in a header such as sRGB ← DeviceCMYK via Japan Color 2001 Coated. CMYK goes through the simulation profile, so a DeviceCMYK red gets the Lab it would really print at, and an RGB black shows how rich it would come out. In Simulation CMYK, DeviceGray and DeviceCMYK are shown as they are: a DeviceGray 0 is K 100, not a converted rich black.

Conversions use relative colorimetric intent with black point compensation.

Simulate: which CMYK#

The simulation profile is chosen in this order:

1. The document’s /OutputIntents profile, when it has a CMYK one (a PDF/X file, typically). The Simulate popup then reads Document: FOGRA39L Coated (or whatever the file declares) and is disabled, because the file has already said what it is for.
2. Otherwise, the profile you pick from the popup. Galley lists the CMYK output profiles installed in the ColorSync folders (system, /Library, your ~/Library) and Adobe’s shared profile folder. Your choice is remembered.
3. On a fresh install, Japan Color 2001 Coated when it is installed, and Generic CMYK otherwise.

A non-CMYK intent, such as the sRGB intent of a PDF/A file, is listed as Document: … (not CMYK, not used) and never used as a CMYK simulation. The Info sidebar lists the document’s output intents under Features.

Separations and TAC#

Below the reading, an Acrobat-style column lists the process plates and every spot color on the page, with the plate values under the cursor and the total area coverage:

DeviceGray lands on the K plate only, Separation and DeviceN on their own plates, and RGB and Lab are converted through the simulation profile and marked ≈. A TAC over the limit is flagged, e.g. TAC 301% ⚠︎ > 300%, which is where an RGB black converted through FOGRA39 lands. The limit is 300 % by default:

defaults write com.github.munepi.galley colorPickerTACLimit 350

Locking a reading#

Click the page to lock the panel on the current reading; the title changes to Color Picker 🔒 Locked, and moving the cursor no longer updates it. Click again to release. Reloading the PDF releases the lock too, since the page the reading came from no longer exists.

Copying a color#

The two keys are the ones Digital Color Meter uses for the same jobs. The panel’s Copy Text and Copy PDF buttons do the same.

Copy Color as PDF carries the color space definition with it. Paste into Illustrator and a Separation arrives as a spot swatch under its own name, and DeviceCMYK arrives as the exact CMYK values, not as an RGB approximation of either. Pasting into a text editor gives the same text as Copy Color as Text.

With Page Color#

Readings do not change under Page Color. Dark, Charcoal and the paper tints alter what is on screen; the picker reads the content stream, which they leave alone. The magnifier draws the page afresh rather than copying the screen, so it too shows the document’s own colors.

What it does not report#

• Soft masks (SMask in an ExtGState). Constant alpha is reported; a gradient mask is not.
• Overprint (OP, op, OPM). A K 100 that overprints reads as plain K 100, and the separations column shows the topmost object’s plates as if everything knocked out; check overprint settings in a preflight tool.
• Annotations — link borders, form widgets and the like. Over one with no ink beneath it, the panel says annotation here (not scanned).
• Optional-content visibility. Content on a hidden layer is still reported as ink.