| name | normalize-color-profile |
| description | Standardize a PDF's color profile — convert to sRGB (default, best for office digital printers) or CMYK FOGRA39 (for commercial print shops). Eliminates color-shift surprises caused by mixed/unspecified color spaces. Triggers on phrases like "normalize colors", "convert to sRGB", "set CMYK profile", "fix weird colors on print". |
Normalize Color Profile
Convert all color content in a PDF to a single, consistent ICC profile.
Why it matters
PDFs accumulate color from many sources — RGB photos from a phone, CMYK ads from InDesign, untagged office-doc colors. Printers interpret unspecified color unpredictably. Normalizing to one profile eliminates that variance.
Inputs
- Input PDF path (required).
- Target profile (optional) — default
sRGB for office digital printing. Other choices:
sRGB — IEC 61966-2.1, the safe default for office laser/inkjet, screens, and most consumer/digital workflows.CMYK-FOGRA39 — ISO Coated v2, European commercial print standard.CMYK-GRACoL — North American commercial print standard.Gray — convert all to grayscale (use color-to-grayscale skill instead for that case).
- Output path (optional) — defaults to
<input>-<profile>.pdf.
Tooling
Ghostscript with pdfwrite and ColorConversionStrategy.
sRGB recipe (default)
gs -o output.pdf \
-sDEVICE=pdfwrite \
-sColorConversionStrategy=sRGB \
-sProcessColorModel=DeviceRGB \
-dCompatibilityLevel=1.4 \
-dEmbedAllFonts=true \
-dNOPAUSE -dBATCH \
input.pdf
CMYK FOGRA39 recipe
gs -o output.pdf \
-sDEVICE=pdfwrite \
-sColorConversionStrategy=CMYK \
-sProcessColorModel=DeviceCMYK \
-sDefaultCMYKProfile=ISOcoated_v2_eci.icc \
-dCompatibilityLevel=1.4 \
-dEmbedAllFonts=true \
-dNOPAUSE -dBATCH \
input.pdf
The ICC profile file (ISOcoated_v2_eci.icc) must be available — install icc-profiles on Debian/Ubuntu, or download from ECI.
Verification
gs -o /dev/null -sDEVICE=inkcov input.pdf
gs -o /dev/null -sDEVICE=inkcov output.pdf
inkcov reports CMYK ink coverage per page; useful sanity check after CMYK conversion.
Workflow
- Probe input color spaces — if everything is already sRGB, skip and report "no-op".
- Confirm target profile with user if unclear.
- Run conversion.
- Verify and report profile of output.
Output
Color-normalized PDF.
