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Re: Measuring colours accurately in mobile apps

for

From: Steve Green
Date: Jun 23, 2021 1:22AM

Thanks, it's good to know we're not missing anything obvious.

Steve

-----Original Message-----
From: WebAIM-Forum < <EMAIL REMOVED> > On Behalf Of Patrick H. Lauke
Sent: 23 June 2021 08:03
To: <EMAIL REMOVED>
Subject: Re: [WebAIM] Measuring colours accurately in mobile apps

We generally go down the "take a screenshot on device, then transfer it to a desktop/laptop device for traditional testing with CCA or similar"
path, despite its potential flaws (for instance, even taking an on-device screenshot can lead to specific colour profiles/adaptations on the device being applied, making the colour drift slightly). And you're exactly right, other methods like Zoom, Reflector, or similar will compress the video leading to changes in colour, and should always be avoided.

When emailing, if given the option, go for "original" rather than any email client resizing. That should guarantee that it takes the raw screenshot that was saved, without any further recompression.

There's no (legal/legit) way to grab an app from the app store/google play store and then decompiling it (especially since these apps are digitially signed etc when packaged).

When reporting on colour contrast failures (and luckily, we only do failures, and don't list all colour combos including passes) we also include wording that explains the values are approximate, based on having to test what was available to us. If a client wants more precision/certainty, we ask for actual accurate colour values they used, or request that they give us access to a development build/XCode project/similar to open in an actual development tool.

P
--
Patrick H. Lauke

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