You can see the lightness and chroma moving within a narrow range as it sweeps the hue. These new color space functions make making palettes like this way easier.
Whats the deal with oklch? My naive reaction was a that it sucks to define colors in a way you can’t easily reason about or need and external tool to make.
Short answer - RGB is really convenient for lighting up sub pixels on your LCD screen, but it's utterly terrible at conveying information about relation between colors. HSL is a clever hack to quickly answer which color is slightly dimmer or brighter than this color, but again, it's quite terrible at conveying information about difference between colors.
I encourage you to think about two random colors and imagining a gradient between them and then drawing said gradient in RGB and HSL color spaces. In both cases it will be wildly different from what you'd expect or could create with two blobs of oil paint on canvas.
Long answer - unfortunatelly it's quite hard to convey why we need a better color space in twitter-space but this video (while 40m long it's quite condensed) is an excellent explainer: https://www.youtube.com/watch?v=gnUYoQ1pwes
OKLCH is really easy to work with. Once you have your palette it's easy to get correct shades and hues by tweaking some values. This works great with CSS custom properties.
oklch and oklab are much easier to reason about than alternatives. For oklch, The first parameter is the lightness, the second is the chroma (essentially its saturation), and the 3rd is the hue. I find it very easy to tweak colors by making them brighter or more saturated. Unlike lch, such changes in oklch have regular effects on how the color will be percieved.
This is the first I've heard of oklch. Here's the perspective of somebody who writes a lot of shaders: It looks similar to Hue/saturation/value encoding, which as tons of uses, but with saturation replaced with "chroma" where it seems to nonlinearly adjust saturation probably based on some perceptual study that makes it extra spicy and high science.
There are three main models to numerically model a color space.
There is an additive color mixing model, which is basically your standard RGB model, where you basically control how bright each of the red, green, and blue lamps shining at a point. There is a complementary subtractive color mixing model, which is controlling the amount of pigments you drop onto a substrate (CMYK is what you'll see used in computers these days). Then there's a third model, where you measure it according to brightness, colorfulness, and then the actual hue it is--there's a lot more variants in this model, basically any colorspace you don't recognize is this kind of model.
If you visualize colors existing in an RGB cube, you have 8 colors at the vertices: black and white are at opposite ends of a diagonal, and the other 6 are two sets of nonadjacent vertices: red, green, and blue in one set, and cyan, magenta, and yellow in the other set. Given such a cube, you should be able to easily see that RGB is using one of those sets as its basis set, whereas CMYK is using the other set as its basis set. The third set of models is built by tilting the cube such that the black-white diagonal is now the vertical line (one of the components), and then distance from this line becomes another component, and then the angle around the line is the final component--it's a cylindrical coordinate space in 3D space, not a Cartesian space.
Some models, like CIELAB or Oklab, use the third model but retain a Cartesian coordinate system, the last two values being called something generic like 'a' and 'b'. Oklch is the same as Oklab, but expressed as cylindrical coordinates, because chroma (colorfulness aka distance from the pure light line) and hue (aka the dominant color of the light) is more convenient for people to work with than a Cartesian system.
OKLCH really shines if you have to interpolate color between two colors (e.g. in space resulting in a gradient or in time as part of an animation) or you just want to change a color without makingnit darker or brighter.
If you interpolate between RGB colors you will get very weird grayish shades inbetween and the new color may be preceptually darker or brighter, which may be a problem (e.g. if it is text on a background). With OKLCH you define one color and as you rotate around the color wheel it stays the same preceptual brightness, which is incredibly cool.
This means before a designer would have to touch 3 values (RGB or HSV) to match the colors preceptually using their eyeballs, now there is only one value and it matched nearly perfectly as it is.
L is for lightness (0-100%), C is for chroma (0-0.5), H is for hue (0-360deg).
Lightness dictates how white or black a color is, chroma dictates how saturated it is, and hue is which angle on the color wheel it occupies. Varying these one at a time lets you intuitively pick colors that are close to one another in the space of human perception. And CIE Lab colors are especially nice because they cover more than the sRGB gamut that we're all used to defining with HSL or RGB, so you can really make the most of your fancy wide color gamut monitor.
The deal with Oklch is that hsl/hsb don’t do a good lightness mapping regarding color perception, but Oklch does. So, if you transform your RGB to lch and move the “l” value, you can easily get a nicer color palette. Also, you can tell the lightness of two colors by looking at the “l” value; that’s not true for hsl/hsb. That’s useful if you want lightness contrast or different hues with a similar lightness.
Other than that, I agree that “chroma” is hard to reason about. But, at least it is easier to reason than the “a”/“b” parameters in “lab”.
I'd argue you can reason about it better, because the space is telling you how the colors actually work perceptually. Trying this tool (https://oklch.com/) it feels like you can get to the color you want quicker. The invalid ranges are a bit of a problem for manually editing these values, though.
This is nice, and works really nice for her use case!
Two things to note when thinking about color schemes:
(1) dr. Cynthia Brewer spent way too much time developing the color scheme for maps with information and similar inforgraphics. I can't find the document at this time, but was a lecture long explanation about how she got them.
(2) designers often use "sacred geometry" bullshit like "golden ratio", PI, Phi, and such to explain their thought process. The most common way to create a color palette is to use opposite colors, "triads" and "tetrads". All of this is based on color wheel in HSL/HSV. Which is almost as bad at describing relation between colors as RGB. [2]
PS. my pet peeve for a long time was trying to understand why most color quantization algorithms were relying on finding the distance between RGB colors in 3D space (by mapping RGB components to XYZ coordinates) while it's obviously a terrible way to reason about color relationship.
PPS. a random dude with a similar interest but way more dedication (re)disovered a work by Kubelka and Munk from 1931 describing an algorithm how to properly mix colors and based on that created an incredible graphics program that allows you to paint just like in real life - with oils and watercolors on canvas! [3]
I think it's rather unpleasant for her use-case actually. I rainbow looks quite nice but when used in a dashboard like that... I don't know, the big solid blocks don't look nice to me. I think they're too saturated. They're nicer for the (outlined) squares and lines, not so nice in the donut graph and for the header backgrounds.
My usual problem with these palettes from color blindness. The two greens are almost identical for the most common type. They don't have good contrast if they're e.g. used for lines in a chart.
The tol palettes are the best looking colorblind friendly palettes to me. Most of the others get complaints from non colorblind users about looking bad/desaturated.
The top comment color palette also reminds me a lot of the viridis "turbo" palette, which is a more perceptually uniform on MATLAB's notoriously bad "jet" palette
I tried to get a palette that would work for colorblind people, but I only made it up to 3-4 colors IIRC. I needed to plot more lines… so I ended up using shapes. My plot could be more beautiful without them, but at least everybody can read it. :shrug:
Cool! I have a palette editor tool that lets you visualise how the hue, saturation and luminance varies over the palette using the HSLuv colorspace (ignore the UI mockup on the left):
I.e. from the first to the last color, the hue increases in even gaps, and the luminance goes from quite dark then gradually brighter up to yellow, then gradually darker again.
> An LCH rainbow colour palette can be created by choosing fixed chroma and luminance values and varying the hue
> Yellow is given the highest luminance, as it only looks yellow when bright.
I find it interesting how hue and luminance are sometimes conflated when talking about colors. "Blue" usually means "blue hue, low to high luminance", and similar for a lot of other colors like green. But "yellow" usually means "yellow hue, high luminance", similar for orange.
If you are showing a gradient, then the colour-blind people of the world will tell you in quite strong terms not to use a rainbow for the scale at all, let alone to use a rainbow that has been designed to have this sort of perceived lightness curve.
The headlined article is a rainbow, not some universally applicable colour scheme.
I think the only way to fix that would be to darken the yellow to the point where it's not really perceived as yellow anymore though - more like a muddy mustard.
edit: op originally specifically referred to yellow.
The 12 bit constraint is a fun one although a little artificial. But picking 12 different colors with constant luminance is quite a challenge! ColorBrewer only goes to 9, and to my eyes more than 6 is very hard to make out. But these 12 are quite nice if you don't mind a little blurring, particularly folks with some form of colorblindness.
Readit News
CSS recently has been adding way more color features, here's the palette represented in oklch:
You can see the lightness and chroma moving within a narrow range as it sweeps the hue. These new color space functions make making palettes like this way easier.I encourage you to think about two random colors and imagining a gradient between them and then drawing said gradient in RGB and HSL color spaces. In both cases it will be wildly different from what you'd expect or could create with two blobs of oil paint on canvas.
Long answer - unfortunatelly it's quite hard to convey why we need a better color space in twitter-space but this video (while 40m long it's quite condensed) is an excellent explainer: https://www.youtube.com/watch?v=gnUYoQ1pwes
OKLCH is really easy to work with. Once you have your palette it's easy to get correct shades and hues by tweaking some values. This works great with CSS custom properties.
This page has more information: https://evilmartians.com/chronicles/oklch-in-css-why-quit-rg...
There is an additive color mixing model, which is basically your standard RGB model, where you basically control how bright each of the red, green, and blue lamps shining at a point. There is a complementary subtractive color mixing model, which is controlling the amount of pigments you drop onto a substrate (CMYK is what you'll see used in computers these days). Then there's a third model, where you measure it according to brightness, colorfulness, and then the actual hue it is--there's a lot more variants in this model, basically any colorspace you don't recognize is this kind of model.
If you visualize colors existing in an RGB cube, you have 8 colors at the vertices: black and white are at opposite ends of a diagonal, and the other 6 are two sets of nonadjacent vertices: red, green, and blue in one set, and cyan, magenta, and yellow in the other set. Given such a cube, you should be able to easily see that RGB is using one of those sets as its basis set, whereas CMYK is using the other set as its basis set. The third set of models is built by tilting the cube such that the black-white diagonal is now the vertical line (one of the components), and then distance from this line becomes another component, and then the angle around the line is the final component--it's a cylindrical coordinate space in 3D space, not a Cartesian space.
Some models, like CIELAB or Oklab, use the third model but retain a Cartesian coordinate system, the last two values being called something generic like 'a' and 'b'. Oklch is the same as Oklab, but expressed as cylindrical coordinates, because chroma (colorfulness aka distance from the pure light line) and hue (aka the dominant color of the light) is more convenient for people to work with than a Cartesian system.
If you interpolate between RGB colors you will get very weird grayish shades inbetween and the new color may be preceptually darker or brighter, which may be a problem (e.g. if it is text on a background). With OKLCH you define one color and as you rotate around the color wheel it stays the same preceptual brightness, which is incredibly cool.
This means before a designer would have to touch 3 values (RGB or HSV) to match the colors preceptually using their eyeballs, now there is only one value and it matched nearly perfectly as it is.
Lightness dictates how white or black a color is, chroma dictates how saturated it is, and hue is which angle on the color wheel it occupies. Varying these one at a time lets you intuitively pick colors that are close to one another in the space of human perception. And CIE Lab colors are especially nice because they cover more than the sRGB gamut that we're all used to defining with HSL or RGB, so you can really make the most of your fancy wide color gamut monitor.
Other than that, I agree that “chroma” is hard to reason about. But, at least it is easier to reason than the “a”/“b” parameters in “lab”.
But the RGB defaults can't be easily reasoned about either, so this is still an improvement, so it's not worse
The loss is no longer having any intuition about what a color is just by seeing the numbers.
Two things to note when thinking about color schemes:
(1) dr. Cynthia Brewer spent way too much time developing the color scheme for maps with information and similar inforgraphics. I can't find the document at this time, but was a lecture long explanation about how she got them.
(2) designers often use "sacred geometry" bullshit like "golden ratio", PI, Phi, and such to explain their thought process. The most common way to create a color palette is to use opposite colors, "triads" and "tetrads". All of this is based on color wheel in HSL/HSV. Which is almost as bad at describing relation between colors as RGB. [2]
PS. my pet peeve for a long time was trying to understand why most color quantization algorithms were relying on finding the distance between RGB colors in 3D space (by mapping RGB components to XYZ coordinates) while it's obviously a terrible way to reason about color relationship.
PPS. a random dude with a similar interest but way more dedication (re)disovered a work by Kubelka and Munk from 1931 describing an algorithm how to properly mix colors and based on that created an incredible graphics program that allows you to paint just like in real life - with oils and watercolors on canvas! [3]
[1] https://colorbrewer2.org/ [2] https://www.youtube.com/watch?v=gnUYoQ1pwes [3] https://www.escapemotions.com/products/rebelle/about
The tol palettes are the best looking colorblind friendly palettes to me. Most of the others get complaints from non colorblind users about looking bad/desaturated.
The top comment color palette also reminds me a lot of the viridis "turbo" palette, which is a more perceptually uniform on MATLAB's notoriously bad "jet" palette
https://www.inclusivecolors.com/?style_dictionary=eyJjb2xvci...
I.e. from the first to the last color, the hue increases in even gaps, and the luminance goes from quite dark then gradually brighter up to yellow, then gradually darker again.
> An LCH rainbow colour palette can be created by choosing fixed chroma and luminance values and varying the hue
> Yellow is given the highest luminance, as it only looks yellow when bright.
I find it interesting how hue and luminance are sometimes conflated when talking about colors. "Blue" usually means "blue hue, low to high luminance", and similar for a lot of other colors like green. But "yellow" usually means "yellow hue, high luminance", similar for orange.
The headlined article is a rainbow, not some universally applicable colour scheme.
Needs more consideration. The colors are not equally different.
edit: op originally specifically referred to yellow.
Obviously designing for bad screens and/or eyes are both very important considerations, though.