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Re: Measuring colours accurately in mobile apps

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From: Glen Walker
Date: Jun 23, 2021 12:39AM

A while back I had tried the "Color Contrast" app but wasn't overly impressed.

https://apps.apple.com/us/app/color-contrast/id1095478187

It still relies on a screenshot or loading a url (which doesn't help with a native app). I haven't tried running two apps on a newer iPad to see if that helps.

Although tedious, I haven't had too much trouble with a screenshot and emailing the image. I don't see any color degradation and even if the color isn't exactly right, it's usually close enough. Unless I'm near 4.49:1, having a color that is close to the original will still either fail when the exact color fails or pass when the exact color passes.

Sent from my iPhone

> On Jun 22, 2021, at 11:02 PM, Steve Green < <EMAIL REMOVED> > wrote:
>
> Does anyone have a method for accurately measuring the text and background colours in mobile apps in order to make colour contrast measurements? For context, we are independent testers, so we never have access to the development environment. Sorry this is a bit long, but it's perhaps the most challenging test process issue we currently have.
>
> Aside from an accessibility scanner app for Android, I am not aware of any tools that can make the measurements on a mobile device. All the methods we have tried involve making the measurements on a desktop machine, which means transferring an image of the device screen.
>
> We have done extensive testing and found that every method we can think of is wildly inaccurate. Such methods include:
>
> * Taking screenshots and emailing them as attachments.
> * Taking screenshots and emailing them as embedded images.
> * Taking screenshots and transferring them through the file system.
> * Screen mirroring using Mobizen and Lonely Screen.
> * Setting up a Zoom call between the mobile device and the desktop machine.
>
> The key findings are:
> * For any given colour in the app, each method of measurement gives a different result. The differences can be massive. None are close enough to be useful.
> * For any given method of measurement, some colours might be measured fairly accurately, but the measurement of other colours is hopelessly inaccurate.
>
> The accessibility scanner app for Android is useful, but only up to a point. It reports the colour values in combinations that do not have sufficient contrast, which is good. However, it does not report the colour values in combinations that pass. That won't bother a lot of people, but our process requires all combinations to be measured and recorded as proof of what the colours were on that day and proof that all combinations were tested.
>
> Also, we don't have any solution for iOS and there is the issue of measuring non-text contrast.
>
> As far as I can tell, the errors are due to compression during the mirroring or streaming process and the different colour spaces on different devices. It is also possible that the screenshot application on mobile devices introduces errors. Images may also be degraded when embedded in emails sent from mobile devices. As such, making the measurement on the mobile device would seem to be best if that's possible.
>
> Are we the only people who don't know how to do this? What does everyone else do?
>
> Is it possible to download an app from the App Store or Play Store and somehow pull it into XCode or another development environment in order to see all the colours? Or are there any decompilers, like we used to use to pull apart Flash movies?
>
> Regards,
> Steve Green
> Managing Director
> Test Partners Ltd
> 020 3002 4176 (direct)
> 0800 612 2780 (switchboard)
> 07957 246 276 (mobile)
> 020 7692 5517 (fax)
> Skype: testpartners
> <EMAIL REMOVED>
> www.testpartners.co.uk
>
> Connect to me on LinkedIn - http://uk.linkedin.com/in/stevegreen2
>
> > > >