Colour: From Hexcodes to Eyeballs →

April 10, 2018 · 14:50

Jamie Wong, on his Zero Wind blog:

Why do we perceive background-color: #9B51E0 as this particular purple?

This is one of those questions where I thought I’d known the answer for a long time, but as I inspected my understanding, I realized there were pretty significant gaps.

Through an exploration of electromagnetic radiation, optical biology, colorimetry, and display hardware, I hope to start filling in some of these gaps. If you want to skip ahead, here’s the lay of the land we’ll be covering […]

This is a fantastic and informative journey through light and colour — I found myself nodding along to the things I knew and being surprised by the rest. Do set aside at least 15 minutes to get through the whole piece without interruptions.

(via @khron)


How Colour Managment Works on iOS 9.3 →

April 22, 2016 · 12:59

Brandon Chester:

With 9.3 iOS essentially has full support for ColorSync in the same way that OS X does. ColorSync has been Apple’s system for color management for many years now, and it works very well in applications that are built on top of Apple’s frameworks like Quartz, Core Animation, and the entirety of AppKit. It just so happens that basically every iOS application is built on these frameworks, and so the task of building system-wide color management in to iOS was seemingly not a difficult one.

Color management appears to be working quite fine across the entire system and within all apps. The interesting thing is, the sign that color management works is the fact that for almost all content there is absolutely no difference between the new iPad Pro and the iPad Air 2. This is expected, as almost all content on the device will target the sRGB gamut, and so if color management is working it should be mapped into the larger DCI-P3 gamut without issue.

Apple’s own applications interpret untagged content as sRGB, and also properly understand tagged images and videos and display them correctly. Safari also renders CSS colors correctly, which is something that can’t be said for any other browser that I’m aware of. The same is true of all third party apps that I’ve tried, including Dropbox, Google Drive, AVPlayerHD, Animuplyr, among many others. While I had worried that iOS’s lack of color management prior to 9.3 would lead to many problems with accurate images on the 9.7″ iPad Pro, Apple has handled the situation better than I ever expected.

The problem with colour management and gamuts is that many computers, tablets, and smartphones can barely display sRGB properly, which means that putting out images which will fit in DCI-P3 is pointless – 99.9% of the people viewing them will not see the correct image. Unless you’re just using the 9.7″ iPad Pro to display photos to family, clients, etc. This could be solved in a number of ways, but none of them are easy at this point in time, nor do I see them being implemented in the near future. We still have a long way to go unfortunately.

Brandon also details how True Tone works and how it affects colour accuracy — I have Night Shift turned off and I would turn True Tone off too (if my 12.9″ iPad Pro had it), perhaps apart from reading sessions.