Why don't my colors look the same on my phone?
Check two separate things: whether the exported file changed, and how the phone's viewer and display interpret that file. Matching pixel values alone cannot establish matching screen appearance. We cannot identify the cause on an unknown phone without its file and viewing conditions. For a browser watermark edit, keep the original and check color information in the actual downloaded copy before blaming the repair.
Our test measures a tagged PNG and its browser download. It does not calibrate a phone, test Lightroom or Photoshop, or prove why somebody else's picture looks different.
Samples
Compare values outside the painted selection.
Description
Inspect the file's color-related chunks and profile.
Display
Keep physical screen appearance separate from file inspection.
What stayed and what did not in our export
We created an owned 480 by 280 RGB PNG with three plain colored swatches and an artificial TEST label near the bottom. We embedded a genuine sRGB ICC profile containing 588 bytes. The input PNG contained IHDR, iCCP, IDAT and IEND chunks. This is a controlled drawing, not a camera photograph or a wide-gamut fixture.
We uploaded it to the unchanged live browser tool, painted only the small TEST label, ran repair and saved the actual Download PNG result. The downloaded image remained 480 by 280 pixels. Comparing every RGBA tuple in the upper rectangle, from the origin to 480 by 180 pixels, found zero changed pixels. Comparing the whole input with the downloaded image found 418 changed pixels. The protected swatches stayed numerically equal in this run; the repair still changed other pixels.
We inspected the saved output rather than assuming the input profile survived. Its chunks were IHDR, IDAT, IDAT and IEND. The input iCCP chunk was absent, and the output contained none of the sRGB, gAMA, cHRM or cICP chunks either. The decoded file inspection returned no embedded ICC bytes. Input and output measured 2173 and 3817 bytes, respectively. Byte length is not a color-accuracy score.
The experiment supports a narrow conclusion: equal swatch values did not mean the exported file retained its embedded profile. It does not establish a visible color error on a phone. We did not measure a physical display, calibrate one, compare applications on different devices or inspect the original questioner's file. The supported read-only browser interface could not expose the canvas context attributes, so its actual colorSpace was not verified.
Read the description as well as the numbers
The PNG specification defines iCCP as an embedded ICC profile describing the color space of image samples. A missing iCCP chunk alone is not a complete color audit: PNG also has other color-related chunks. That is why we listed what was actually present in our downloaded fixture, rather than treating the absence of one chunk as proof of every possible interpretation.
Browser canvas documentation also distinguishes requested context parameters from the parameters actually supported. A file inspection cannot substitute for reading those parameters, and neither measurement substitutes for a calibrated physical display. We have no evidence here for a device-specific setting that fixes every mismatch.
After a watermark edit
Use the same untouched input and actual exported copy when investigating the change. Compare the unselected picture area separately from the repaired mark, then inspect the file's color description. If the mismatch only appears in a particular viewer or screen, the cause still needs evidence from that viewing path. Do not keep adjusting saturation blindly and call the result preserved.
The browser watermark tool fills a painted area with nearby pixels. It does not run a generative model, recover hidden original detail or calibrate a display. Central marks require the manual brush; automatic edge mode is only a trial for a small high-contrast edge mark. Use your own images or files you have permission to edit.
Transparency is a separate check. Our PNG alpha test measures transparent values, not physical color matching. This color-profile experiment cannot establish photographic quality, HDR preservation or a universal guarantee across phones.