How can I make a PDF's color choices easier to read in grayscale?

Look for any place where color carries meaning rather than merely decorating the page. In a chart, that might be the only way to tell one series from another. In a diagram, it might identify a route or category. In text, color might be the only indication that a word is important or that an item has a particular status.

Review a grayscale view or printout, if available, and ask: “Could someone identify this item and understand its role without knowing its original color?” Don’t stop at whether the shades look different. The key question is whether the distinction is explained clearly enough to use. Adobe’s Acrobat Pro accessibility report includes a color-contrast check that can flag possible problems, but Adobe notes that it does not establish whether each item is essential and that some checks need manual review. [S1]

Give each series another distinguishing feature and explain what it represents. Depending on the chart, you might use different line patterns or point symbols, place labels next to the lines, or add a clear key that names each series. Don’t rely on a legend’s colored swatches alone if readers still have to match indistinguishable shades to the chart.

For example, suppose a chart compares “Planned” and “Actual” values. A grayscale-friendly revision could use a solid line with circle markers for Planned and a dashed line with square markers for Actual, plus direct labels at the line ends. Those are illustrative choices, not rules for every chart: check that the marks remain visibly distinct in your PDF and that the labels are easy to associate with the correct series. If a chart is too crowded for direct labels, consider a less crowded layout or clearer accompanying explanation.

Add the meaning in words or a symbol, not just in the color. A red status label, for instance, could say “Overdue” rather than relying on red alone. A highlighted instruction could also have a heading such as “Important” or an accompanying icon with a clear text explanation. In a map or diagram, label the relevant area or route directly where practical.

Check the result in context. A symbol that is not explained may be just as ambiguous as a color, and a label placed far from the item may be hard to match. The aim is not to remove every color choice; it is to make the information understandable when those colors are unavailable.

Use it as one part of the review, not as the final decision. Adobe describes running Acrobat Pro’s Prepare for accessibility > Check for accessibility and reviewing the report. Its color-contrast check can flag possible color-accessibility problems, but it does not determine whether each item is essential, and some checks require manual review. Adobe recommends checking against WCAG 1.4.3; the cited guidance does not describe a dedicated grayscale-simulation procedure or prove that a PDF will remain understandable in grayscale. [S1]

A practical final pass is to review the report, inspect each meaningful color distinction in grayscale, and revise any item whose purpose is unclear without color. Then check the revised PDF again. Keep a short record of anything you could not verify, such as a complex chart that needs review by its author.