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What are OKLCH colors?

jakub.kr

31–40 of 189 posts

Re: What are OKLCH colors?

#32
post #10

Wherever you're working with colors and text/emblems, please also consider contrast and legibility: https://apcacontrast.com/ >

While the above site is great for measuring with a modern contrast algorithm (it’s the current algorithm for the yet-to-be-released WCAG 3 accessibility standards), it’s worth bearing in mind that the WCAG 2 algorithm is somewhat different, and a legal requirement in many markets / industries. You can check your colours against that with a tool like https://www.siegemedia.com/contrast-ratio , although there are many…

You can pick colors that pass both APCA and WCAG contrast checks though so it's not a problem to use APCA recommendations now.

I find APCA is a little stricter than WCAG for light themes, and APCA is much stricter than WCAG for dark themes, to the point where you really shouldn't use WCAG for dark themes. So most of the time APCA is giving you stricter contrast that easily pass WCAG also.

I keep seeing mentions that APCA will let you finally use e.g. white on orange, or white on vibrant blue that pass APCA but fail on WCAG, but my feeling is there's not a lot of examples like this and most of these pairings only have okay contrast anyway, not great contrast, so it's not ideal to be stuck with WCAG's false negatives but not that big of a deal.

Re: What are OKLCH colors?

#33
post #5

I've not touched oklch, but I've played with oklab gradients a fair amount. How do they (oklch & oklab) compare for different uses?

oklch uses the oklab color space.

The oklch color space is polar: it’s a cylindrical transformation of the oklab cartesian color space.

Re: What are OKLCH colors?

#34
These IP addresses being released at some point, and making their way into something else is probably the reason I never got to fully run my mailserver from my basement. These companies are just massively giving IP addresses a bad reputation, messing them up for any other use and then abandoning them. I wonder what this would look like when plotted: AI (and other toxic crawling) companies slowly consuming the IPv4 address space? Ideally we'd forced them into some corner of the IPv6 space I guess. I mean robots.txt seems not to be of any help here.

Re: What are OKLCH colors?

#35
post #34

These IP addresses being released at some point, and making their way into something else is probably the reason I never got to fully run my mailserver from my basement. These companies are just massively giving IP addresses a bad reputation, messing them up for any other use and then abandoning them. I wonder what this would look like when plotted: AI (and other toxic crawling) companies slowly consuming the IPv4 ad…

I think you commented on the wrong post :)

Re: What are OKLCH colors?

#36
post #19

Earlier quoted context omitted.

Very interesting. Is this just a limitation of our current hardware? How much of this problem would still exist if everyone had a wider gamut monitor, say full DCI-P3? That still doesn't cover the full gamut of Oklch, but would it make the problem practically disappear?

No. We’re talking about colours way beyond the ranges of human perception. For this specific gradient, see https://oklch.com/#0.7017,0.3225,328.36,100 and https://oklch.com/#0.86644,0.294827,142.4953,100 , and look at the Chroma panel, see how far out of our screen gamuts they are (even tick “Show Rec2020”, which adds a lot of chroma around blue–green and magenta–red), and try to imagine the colours between the lime…

I don't get it, why am I seeing the "out of gamut" colors if my sRGB monitor is unable to display them? Would the charts look different on a P3 monitor?

edit: Also, you mentioned the colors "beyond the ranges of human perception" but I don't think there is any such limitation here, the bottleneck is the hardware (computer monitors).

Re: What are OKLCH colors?

#37
post #35
post #34

These IP addresses being released at some point, and making their way into something else is probably the reason I never got to fully run my mailserver from my basement. These companies are just massively giving IP addresses a bad reputation, messing them up for any other use and then abandoning them. I wonder what this would look like when plotted: AI (and other toxic crawling) companies slowly consuming the IPv4 ad…

I think you commented on the wrong post :)

Oops,haha, you're right! Should have been https://news.ycombinator.com/item?id=45010183

Apologies! (I can't delete the post though, feel free to down-vote into oblivion)

Re: What are OKLCH colors?

#38

Earlier quoted context omitted.

While the above site is great for measuring with a modern contrast algorithm (it’s the current algorithm for the yet-to-be-released WCAG 3 accessibility standards), it’s worth bearing in mind that the WCAG 2 algorithm is somewhat different, and a legal requirement in many markets / industries. You can check your colours against that with a tool like https://www.siegemedia.com/contrast-ratio , although there are many…

You can pick colors that pass both APCA and WCAG contrast checks though so it's not a problem to use APCA recommendations now. I find APCA is a little stricter than WCAG for light themes, and APCA is much stricter than WCAG for dark themes, to the point where you really shouldn't use WCAG for dark themes. So most of the time APCA is giving you stricter contrast that easily pass WCAG also. I keep seeing mentions that…

If your colours have enough contrast to pass them both then of course that’s fine!

I only bring it up because I had a situation last week where the better APCA was giving results for both white-on-colour and #111-on-colour as suitable for headline copy under WCAG3, but #111-on-colour was 7.5:1 and white-on-colour was 2.5:1 under WCAG2, hence we could only use one of them legally.

Re: What are OKLCH colors?

#40
On the comparison between Color spaces, it's weird, my monitor from 2008 does show a difference between the Display-P3 and the sRGB purple colors, yet I didn't think it'd have such a big color range. Is there some color conversion at the browser or OS-level? (my distro/desktop enables colormgr by default).
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