WebAIM - Web Accessibility In Mind

E-mail List Archives

Re: Measuring colours accurately in mobile apps

for

From: joe@a11yeval.com
Date: Jun 29, 2021 8:39AM


Hi Steve,

I just grabbed the first app could find that I was ok downloading. The colors for the login screen were (possibly) not correct because they were colors over an image-based background which is inaccurate with most (probably all) tools except manually picking or getting the hex values from the designer. I didn't actually test the colors so my comment was a guess.

The Accessibility Inspector is not perfect so it can miss contrast issues, but it can help. Don't chastise, this may help others on the list.

Thankx,
Joe Humbert, CPWA
Accessibility Champion
Android & iOS Accessibility Novice
Twitter: @joehumbert

-----Original Message-----
From: WebAIM-Forum < <EMAIL REMOVED> > On Behalf Of Steve Green
Sent: Tuesday, June 29, 2021 10:26 AM
To: WebAIM Discussion List < <EMAIL REMOVED> >
Subject: Re: [WebAIM] Measuring colours accurately in mobile apps

Hi Joe,

Thanks ever so much for the video. That looks like what we have been doing, so I suspect that my colleague has been testing apps that didn't have any colour contrast failures, in which case I will chastise him appropriately for wasting our time.

Nevertheless, it's interesting that the colour measurements in your video are completely wrong, as you noted. I will investigate that when I get my Mac back.

Steve


-----Original Message-----
From: WebAIM-Forum < <EMAIL REMOVED> > On Behalf Of <EMAIL REMOVED>
Sent: 29 June 2021 14:57
To: 'WebAIM Discussion List' < <EMAIL REMOVED> >
Subject: Re: [WebAIM] Measuring colours accurately in mobile apps

Hi Steve,

Having worked for a consulting firm for 4 years where 90% of the time we did not get source code access to the app, but instead downloaded directly from the App store, I think he might be missing something.

Video link (300MB ::sigh:: QT non-compression): https://www.dropbox.com/s/fyx4blvh3pisf0m/Using%20Accessbility%20Inspector%20on%20App%20from%20App%20Store.mov?dl=0

Link will be deleted in 2 days!

Note: The video has no audio.

Accessible Alternative for video: It shows me downloaded the Hulu App from the App store and opening it, Opening Accessibility Inspector, Choosing my iPhone as the target devices, running an audit on the Hulu app and then showing a (possibly not valid) color contrast issue with provided hex values for foreground and background colors.

I have no professional affiliation with Disney, Hulu or any related companies at this time.

Thankx,
Joe Humbert, CPWA
Accessibility Champion
Android & iOS Accessibility Novice
Twitter: @joehumbert

-----Original Message-----
From: WebAIM-Forum < <EMAIL REMOVED> > On Behalf Of Steve Green
Sent: Tuesday, June 29, 2021 3:25 AM
To: WebAIM Discussion List < <EMAIL REMOVED> >
Subject: Re: [WebAIM] Measuring colours accurately in mobile apps

Thanks, Joe. Are you sure you can do a colour contrast test on apps from the App Store? I don't have a Mac at the moment, but one of my team says that he can do a colour contrast test on an app he has developed, but he can't do it on an app from the App Store. Having seen the video you linked to, I am sceptical of what he is telling me, but I can't check it. Is he missing something?

Steve


-----Original Message-----
From: WebAIM-Forum < <EMAIL REMOVED> > On Behalf Of Joe Humbert (A11y)
Sent: 23 June 2021 12:59
To: 'WebAIM Discussion List' < <EMAIL REMOVED> >
Subject: Re: [WebAIM] Measuring colours accurately in mobile apps

Accessibility Inspector that comes with Xcode on MacOS will allow you to get accurate colors if they fail certain criteria. You can use this with any Application (your own developed, client source code, or Apps from the app store). You will need to connect you iOS/iPadOS device to a Mac with Xcode installed. I think you need to register the device with Xcode, but then it will work.

https://developer.apple.com/videos/play/wwdc2019/257/

I can probably do a screen recording tomorrow and send a link.

For Android, Accessibility Scanner will get you the colors, but not the font sizes or weights. I don't remember off the top of my head if Accessibility Inspector's Audit gives the font size/ weight.

Thankx,
Joe Humbert, CPWA
Accessibility Champion
Android & iOS Accessibility Novice
Twitter: @joehumbert

-----Original Message-----
From: WebAIM-Forum < <EMAIL REMOVED> > On Behalf Of Steve Green
Sent: Wednesday, June 23, 2021 3:22 AM
To: WebAIM Discussion List < <EMAIL REMOVED> >
Subject: Re: [WebAIM] Measuring colours accurately in mobile apps

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

https://www.splintered.co.uk/ | https://github.com/patrickhlauke https://flickr.com/photos/redux/ | https://www.deviantart.com/redux
twitter: @patrick_h_lauke | skype: patrick_h_lauke