Lossless encoding preserves the image supplied to the encoder; it does not undo a prior reduction to a smaller palette. An indexed PNG can store fewer distinct colors than the original RGB photograph. Compare the exported image with the full-color master and inspect the color-reduction settings before blaming PNG compression. Choose an output appropriate to the image rather than assuming every PNG preserves the same color representation.
Inspect the conversion before the save
Look at a smooth wall, a skin gradient and a small colored detail. Determine whether the export workflow converts the image to indexed color, limits its palette or applies dithering. Tiny dots may be a deliberate way to approximate intermediate tones; they are not necessarily new camera noise.
Adobe's indexed-color conversion documentation describes palette and dithering choices. Those settings concern color reduction. They should not be confused with a claim that the final compression algorithm invented or removed a photographed object.
Make a controlled color comparison
- Retain the original RGB master and note its actual color mode.
- Export a full-color reference without the suspected palette reduction.
- Export a separate indexed-color test with recorded settings.
- Compare gradients, small colored details and transparent edges.
- Inspect both files at the intended display size and choose the acceptable one.
For a flat illustration, a restricted palette may be an intentional, useful choice. For a portrait with soft skin tones, the same reduction may become conspicuous. Evaluate each job on its actual visual requirement rather than applying one smallest-file preset to every image.
Return to the master for a repair
Converting a reduced image back to RGB does not restore colors already discarded. It changes what further edits can represent. Re-export from the full-color source when available and compare the new derivative with it. Keep both settings and source identity in the handoff notes.
Is dithering always a defect?
No. It can help represent intermediate tones in a restricted palette. Judge the visible pattern and color transitions at delivery size; do not remove it without comparing the alternative.
Does using a larger file prove better color?
No. Inspect the mode, conversion and actual pixels. Metadata, compression settings and unused padding can affect size without restoring the gradient you need.
Sources and scope
This is an original Imagild Editorial workflow guide, assisted by AI and reviewed against the linked sources on October 12, 2026. External tool procedures do not imply that Imagild provides those tools or guarantees their results.