[HN Gopher] Data Viz Color Palette Generator (For Charts and Das...
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       Data Viz Color Palette Generator (For Charts and Dashboards)
        
       Author : gregwolanski
       Score  : 109 points
       Date   : 2025-09-25 13:13 UTC (9 hours ago)
        
 (HTM) web link (www.learnui.design)
 (TXT) w3m dump (www.learnui.design)
        
       | smjburton wrote:
       | This is great, thank you for sharing. I need something like this
       | for my current project I'm working on... Much easier than trying
       | to build a color palette manually.
        
       | jdonaldson wrote:
       | I also recommend Color Brewer, which is integrated already in a
       | lot of visualization tools, and has great options for display
       | variants and accessibility options :
       | https://en.wikipedia.org/wiki/ColorBrewer
        
       | xipho wrote:
       | Related, the OG, with research behind it-
       | https://colorbrewer2.org/.
        
       | jacomyal wrote:
       | It's functionally very close to https://colorbrewer2.org, which
       | has been online for more than 15 years. I think it's not a
       | coincidence, and some credits wouldn't have hurt anyone...
       | 
       | Also, I have personally been using iWantHue to generate large
       | palettes for more than 10 years now, and I'm still very happy
       | about it: https://medialab.github.io/iwanthue/
        
       | dleeftink wrote:
       | See Fabio Crameri's colour maps for accessible yet pleasing
       | schemes and gradients to accustom various vision impairments
       | [0][1]. Ben Jann's collection also provides a valuable resource
       | and inventory of recent and historic colour schemes included in
       | different statistical packages [2].
       | 
       | [0]: https://www.fabiocrameri.ch/ws/alt-
       | imgs/w800/f19552bb8a98e32...
       | 
       | [1]: https://www.fabiocrameri.ch/colourmaps/
       | 
       | [2]: https://repec.sowi.unibe.ch/stata/palettes/colors.html
        
       | dark-star wrote:
       | Definitely not colorblind-friendly (color contrast too low)
        
         | dleeftink wrote:
         | The default palette essentially is IBM's Color-blind safe[0],
         | which does provide some 'safe' defaults. IBM's design
         | guidelines provide some sound advice for color use too [1].
         | 
         | [0]:
         | https://davidmathlogic.com/colorblind/#:~:text=Three%20of%20...
         | 
         | [1]: https://www.ibm.com/design/language/color/
        
       | tethys wrote:
       | Whenever I need colors for a chart, I type "12 bit" in my address
       | bar and pray my browser hasn't forgotten the URL:
       | https://iamkate.com/data/12-bit-rainbow/
        
         | PythagoRascal wrote:
         | Adding another link, here's the one I often use:
         | https://flatuicolors.com
        
         | a1o wrote:
         | Those are very good colors!
        
         | mpetroff wrote:
         | Please don't use rainbow-type palettes, as they generally have
         | poor accessibility for colorblind individuals. With my red
         | deficiency, the middle two colors in this palette look
         | virtually identical.
        
           | tethys wrote:
           | Fair point! My eyes are (mostly) fine, but even I would have
           | a hard time telling these colors apart when used in the same
           | chart.
           | 
           | I usually do very simple charts, using maybe 2 or 3 colors,
           | and with this palette I feel the results are typically very
           | pleasing, whichever colors I end up selecting.
        
           | Ancapistani wrote:
           | This is super interesting to me.
           | 
           | Is there another 12-color palette that allows you to easily
           | distinguish between every color? If so, I'd love to see it.
           | 
           | I'd also appreciate if anyone who happens to read this who
           | has a different variety of colorblindness - or who finds
           | color palettes inaccessible for any reason - could share what
           | colors in the 12-bit palette and any others that are
           | suggested in this thread are problematic and why, that'd be
           | awesome :)
           | 
           | My initial instinct is that finding 12 colors that are
           | visually distinguishable for all users is likely impossible.
           | That being the case, the ideal solution IMO is likely
           | something like providing a dynamic option to change the
           | palette (or even the representation!) and then choosing a
           | default that the author is happy with.
        
             | mpetroff wrote:
             | > My initial instinct is that finding 12 colors that are
             | visually distinguishable for all users is likely
             | impossible.
             | 
             | Without going to lightness extremes, I agree that this
             | likely isn't possible, at least when trying to accommodate
             | all three types of dichromacy and for small color patch
             | sizes (like those typically used for line and scatter
             | plots). For example, you could take the 10-color accessible
             | palette from work I've published [1] and add black and
             | bright yellow to get twelve colors, but the lightness
             | extremes of adding these colors would result in
             | significantly-different visual weights. Based on a
             | validation survey I conducted, I think even ten colors is
             | pushing the limit of what's reasonable when lightness
             | extremes aren't used.
             | 
             | > could share what colors in the 12-bit palette...are
             | problematic
             | 
             | #9d5 and #4d8 is the color pair I find particularly
             | problematic.
             | 
             | [1] https://arxiv.org/abs/2107.02270
        
           | Ancapistani wrote:
           | I understand there's no direct way to answer this, but does
           | this image appear the same as the live page to you?
           | 
           | https://imgur.com/a/nZnr0BN
           | 
           | If so... wow. That's not good at all; it's almost as hard to
           | distinguish the minimum value from the maximum value as it is
           | the two in the center.
        
             | mpetroff wrote:
             | While not completely identical, it looks very similar (I
             | also only have strong protanomaly, not complete protanopia,
             | so I wouldn't expect it to look identical).
             | 
             | Color-vision deficiency simulations collapse colors along
             | the confusion lines, but this can be done multiple ways.
             | These different mapping will all look the same (and
             | identical to the original) to a dichromat but will appear
             | different, with different perceptual differences between
             | colors, to a color-normal individual. Simulating in a way
             | that accurately portrays perceived color distances is still
             | an open research problem.
        
       | Western0 wrote:
       | I need output: * gnuplot pallete * css for web page
        
       | developer5502 wrote:
       | I like using https://coolors.co/ - press space to generate a new
       | palette and lock in colours you like
        
       | jjgreen wrote:
       | Strange that the SVG output is just a set of colour boxes, when
       | SVG has a perfectly decent gradient format defined.
       | 
       | https://developer.mozilla.org/en-US/docs/Web/SVG/Tutorials/S...
        
       | shash wrote:
       | I was just actually showing a colleague perceptually uniform
       | color scales just today!
       | 
       | https://colorcet.com/
        
       | clintmcmahon wrote:
       | This will come in very handy for me. Thanks for working on this
       | and putting out there.
        
       | divbzero wrote:
       | Does using a range of hues generate colors that can be
       | differentiated by those of us who are color blind?
        
       | cush wrote:
       | Careful, this is really not good for folks who are color blind.
       | In chromium devtools you can enable various color blind
       | emulations in the device emulation menu. ctrl+shift+P ->
       | "Protanopia"
        
         | Ancapistani wrote:
         | Ohhh, that's a great tool that I didn't know existed. I've used
         | GPU-based filters in the past for this.
         | 
         | For others - this panel is shown at the bottom, alongside the
         | "Console" panel (not the "Console" tab at the top!) that's
         | sometimes shown. You can open it by clicking the three vertical
         | dots at the top right of the devtools panel, "More tools", then
         | "Rendering".
         | 
         | The setting you're looking for is "Emulate vision
         | deficiencies".
        
       | Borg3 wrote:
       | Hah, what a coincidence. I did small research today for heatmaps
       | for my very simply graph lib for Ruby. I recommend this blog
       | post:
       | 
       | https://research.google/blog/turbo-an-improved-rainbow-color...
       | 
       | I myself implemented 4 colorize functions for that. Common linear
       | Blue -> Red. Linear Blue -> Red adjusted via Green for
       | visibility. Blue -> Yellow -> Red also linear. And of course
       | Turbo from that blog..
        
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       (page generated 2025-09-25 23:01 UTC)