ManYue: Check PDF page colours with a self-made reference sheet

ManYue 2.0.4 publicly reports a fix for colour-display issues on some PDF pages. That does not mean every PDF has undergone professional colour validation. Build a simple shareable reference sheet and separate the source file, reader display and device conditions. The aim is a reproducible issue record, not an assessment of print colour accuracy or an alteration of the comic original to conceal a display problem.

Make a labelled reference PDF

In an external document tool you know, create a three-page PDF and retain the editable original. Page one should contain a white background, black text and three solid patches labelled red, green and blue. Page two should contain five grey patches ordered light to dark, with that order written down. Page three should contain an ordinary photograph you took and a page number. Colour names identify regions; they do not assert a professional output colour space. Record the export tool, date and filename, and avoid passwords or special interactive content. If you cannot create one, use a simple PDF you own and can share, stating which reference regions it lacks.

Check the source before blaming display

Open the exported original in an independent PDF viewer. Check the three-page count, labels and patch positions, and confirm that export did not turn every grey patch black or white. Record the viewer name and version instead of relying on memory that it looked normal elsewhere. If that viewer has the same missing content, inspect the export tool and content first rather than continuing to attribute the issue to ManYue. Similar output in two viewers establishes similarity for this sample under these conditions, not absolute colour-management correctness. Keep the file identical so that a later exported revision is not accidentally used for comparison.

Fix device and reading conditions

Compare on the same device and record system version, ManYue version, screen orientation and reader theme. Note any active night colour-temperature, inversion or other display-assistance setting. You may choose whether to adjust it temporarily, but record any change and restore it afterwards. Do not judge differences by moving screenshots to another unexplained display. A reader theme may change the surrounding background, so distinguish that from a change to the white area inside the PDF. Keep zoom and page position comparable rather than comparing a whole page on one side with an enlarged photographic detail on the other.

Inspect fixed regions after import

Import the sample through the normal local workflow. On page one, first check that the white background and black text retain a clear boundary, then inspect the three labelled patches for obvious colour substitution, missing regions or broad darkening. On page two, check whether the five greys remain distinguishable in their original order. On page three, check that the photograph is present and the page number correct. Record page, region, expectation and observation for each item, for example that the third and fourth grey patches on page two cannot be distinguished. Do not claim a numerical colour difference from visual inspection: this exercise uses neither a colourimeter nor calibrated-display procedure.

Separate theme changes from content changes

If a difference is obvious, first inspect it again under the recorded theme without simultaneously changing theme, orientation and file. You may then change only one visible reading-appearance option and compare the PDF patches separately from the area outside the page. If only the surrounding background changes, record an interface-appearance change. If a white region inside the PDF also changes, record the region and option without inventing the processing algorithm. Skip this part if no relevant option exists; do not invent a Disable Colour Enhancement button. Necessary cropped screenshots can clarify comparison, but retain page numbers and labels and use only content you may share.

Reopen to check consistency

Leave the reader for the local shelf, reopen the same entry and locate page one and the original affected region. Record whether the issue remains, occurs only on some loads, or changes after the page finishes displaying. Do not flip repeatedly before display completes and mistake a placeholder for final colour. If a real comic PDF is affected while the reference sample is normal, preserve that distinction. A simple sample cannot cover every PDF’s transparency, image encoding or colour information. A shareable minimal sample is more useful to a developer than an entire restricted comic or a claim that every PDF is affected.

Do not damage the original to compensate

If only ManYue displays the sample abnormally, preserve file identity, version, page, conditions and screenshots before reporting it. Do not first brighten, invert or recompress the entire original to compensate: that combines source changes with the display issue. If you temporarily read in an independent viewer, identify it as an alternative reading method, not a repair within ManYue. If both viewers are affected, inspect the source. If the issue occurs only under a device display setting, record that dependency, restore the setting and check again. Change one condition at a time and retain an unconfirmed status when reproduction fails.

Finish with a reproducible colour-check record

Finish by listing the reference file’s three-page structure, size, export tool, both viewing environments, theme and results. Specify normal regions and unresolved ones. Leave the app and return, checking the original affected region and one normal region rather than retaining only a successful screenshot. Restore device display settings changed for the exercise, and retain both the original PDF and editable source. The result supports only a display observation for this sample under the recorded conditions. It is not professional colour certification and does not establish identical behaviour for all comics, devices or future versions.

Related guides and sources

Read PDF comics in ManYue: covers, wide pages and reading position; Checking transparent comic pages in ManYue: background compositing versus missing lines.

Checked on November 7, 2026: Apple public version information lists ManYue 2.0.4, requiring iOS / iPadOS 15.0 or later. Feature scope follows the official App Store description and the installed version. This article provides reading and checking methods you can perform; it does not claim step-by-step physical-device or private-server testing. Manual records, external tools and actually visible controls are identified separately, and personal analysis or code observations are not presented as verified automatic capabilities.