Broken HCL Creator [fixed]

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Dear user,

I just noticed that one of our two “Online HCL Creator” mirrors was not working anymore as the server has changed to https. The issue should be fixed, sorry for any inconvenience.

There will be a shiny version of the HCL wizard in a few weeks which might also increase the usability of the online HCL color creator. I already announced a shiny version last Mai last year, well, this time I promise the tool should be online soon as most work is already done.

Thanks and all best,

Thank you for your interest


Dear visitor

The publication “Somewhere Over the Rainbow: How to Make Effective Use of Colors in Meteorological Visualizations” just got one of the ten most read articles within the last 12 months in BAMS. That makes me optimistic that we can expect  effective figures and plots in the near future.

I would like to say thanks to all of you for your interest, and for the good inputs we got during the last months :).

All Best,

New export button


Hello everyone

Another small update today. I got asked by Arne Spekat if it would be possible to have an export button to download a tailored color palette. Of course it is :).

The Online HCL Creator now offers a Download-Button (choose your personal palette and open the “Export Options: RAW” panel) for the three different types (RGB float, RGB integer base, and HEX colors). The tool then sends a clean ASCII (simple text file) to your browser. If there is a need to change/extend the format for an easier use – please let me know!

Have a nice day,

Typo in BAMS article


Dear user

For those who tried to reproduce the color palettes from the BAMS paper “Somewhere over the rainbow“: there is a typo in table SB1 concerning the second hue for figure 4c. The  second (last) hue should be 320 instead of 230 as I wrote in the article. Thanks to Evan who pointed it out. For R-users: below you can get the code we used to create the color palette (plus the one with the “wrong hue” as printed in the article):


However, the “wrong” version does not violate the concept presented in the paper. The only difference is that the hue only changes between 80-230 (blueish) while the presented figure 4c is using hue’s between 80-320 (violetish).

Sorry for any inconvenience caused by this typo! All best,

Shiny Version


I am currently working on a shiny version of the HCL wizard to increase the accessibility, functionality, and the up-time of the color scheme creator. Therefore some software updates are necessary.

If the alternative version of the HCL color creator does not work it is possible that I am doing some maintenance. However, the ‘eeecon-version of the HCL Creator‘ should work all the time as I dont touch the backup system at the moment. Thank you for your understanding!

Best wishes,

Troubles with the update?

Coding Bug

Dear HCL-Wizard user

It has come to my notice that the new back-end causes troubles in some browsers. Thanks to dchogan for leaving a comment.  I’ll have to check the scripts again to find the reason therefore as soon as I can find some free time. I am sorry for any inconvenience!

For those who have problems with the Online HCL Creator: the “old” version is still online and can be found in the sub-menu of the “Online HCL Creator” button in the navigation. This version is unchanged and should work as before.

Thank you for your understanding and best wishes,

Back-end Updated


Done, we are back online.

I was maintaining the back-end of the “Online HCL Creator” the last few minutes/hours. Sorry for any inconvenience. However, some bugs should be fixed now and the speed of the tool should be better than before. The limit was the webserver. The updated back-end now uses another server with slightly more resources which should hopefully decrease the waiting time while changing the color schemes.

The next few days I will screen the tool to find hidden bugs – if there are any. If you find some it would be great if you could send me a message (reto.stauffer -at- Thank you very much :).

All best,

Campain against rainbow color palettes


Today I received an e-mail from a college about a campain against rainbow color paettes in climate science. The campain was started by Ed Hawkings, Doug McNeall, David Stephenson, Johnny Williams, and Dave Carlson working in different institutions in Europe.
It’s nice to see that different groups try to inform the users on how to use better color schemes than the default ones. More information can be found on their website and on twitter using the #endrainbow hashtag. The original e-mail by Dough McNeall:

Hi all,

A group of scientists (including me) have written an open letter to the climate science community, calling for people to use alternatives to the default “Rainbow” type colour scheme.
Rainbow can distort perception of data, and can be useless for those with colour blindess (about 8% of the male population, 0.4% of the female population).

The letter is mirrored here on my data visualisation blog.

We’d really appreciate your support, comments (negative or positive), resources, and ideas.
We’re also making a pledge not to write papers using the Rainbow colour scheme.


Best wishes, Reto

Hello and welcome!

Colorspace Navigation

I would like to welcome you on this webpage. As you have maybe seen the domain name is not really connected to the content of the page. The page is currently running on a personal webspace and is still under development. In the near future we would like to be reachable on a more obvious domain.

So, what is this page about? During the last few months we were working with a color space called Hue-Chroma-Luminance (HCL) which has a lot of benefits compared to the Red-Green-Blue (RGB) color scheme which is mostly used. This page will give you some information what the HCL color space is, where the problems of the RGB color space are and how to use the HCL space for your personal work. Furthermore there is an online interface where you can create your own color palettes and directly use them for your current projects if you like.

Best wishes
Reto Stauffer