
Completely Painless Programmer's Guide to XYZ, RGB, ICC, XyY, and TRCs - nkurz
http://ninedegreesbelow.com/photography/xyz-rgb.html
======
wpietri
For the merely curious, my recommendation is that you carefully not learn
about this stuff unless you need it for something.

I built an automated lighting system for my house using Hue bulbs. I wanted to
have more "natural" light throughout the day. Ignoring a warning from a friend
("It's as bad as knowing about kerning," he said), I learned a fair bit about
color, including the very mutable and slippery concept of "white".

I like my automated lighting system just fine, but the downside is that I now
notice color temperature of lightbulbs. It's as annoying; things that were
previously fine are now the sources of enduring irritation. So now I'm the
apparently crazy person at work who unscrews lightbulbs and moves them around
my work area because somebody has randomly scattered very-warm-white and very-
cool-white bulbs around the place with no attention to aesthetics or utility.

I was honestly happier not knowing. There are some things you can't unsee, and
color temperature is one of them. I'm glad I could stop before I understood
how bad the color representation is on my various screens.

~~~
revelation
You should try f.lux [1], it will drive you up a wall.

[1]: [https://justgetflux.com/](https://justgetflux.com/)

~~~
versteegen
Redshift does the same thing (supports Windows and X11), no idea what the
difference is. Apparently at the time redshift was created 6 years ago f.lux
didn't work properly on GNU/Linux.
[http://jonls.dk/redshift/](http://jonls.dk/redshift/)

~~~
dmm
Redshift is free (libre) software and fl.ux is "patent pending".

------
jacobolus
This description is _not_ painless. It gets into the technical weeds before
giving a good big-picture overview, which in my experience trying to teach the
basics of human vision and color science usually makes people fall asleep or
start walking away before they learn much. In this particular case, the
technical pieces are also a very narrow and decontextualized, which as
curriculum always results in severe misconceptions. This is a subject that
desperately needs to be taught with many diagrams and pictures, and absolutely
must begin with a basic explanation of how eyes work. Just linking to
Wikipedia doesn’t cut it, as unfortunately the relevant articles on Wikipedia
aren’t very good.

Unfortunately there aren’t any especially good concise explanations of color
science on the internet to link to.

These SIGGRAPH 2001 notes are okay but leave a lot out and don’t include
enough pictures:
[https://graphics.stanford.edu/courses/cs448b-02-spring/04cdr...](https://graphics.stanford.edu/courses/cs448b-02-spring/04cdrom.pdf)

The best online resource I know is
[http://www.handprint.com/LS/CVS/color.html](http://www.handprint.com/LS/CVS/color.html)
but it’s very long and kind of rambling.

Some layman-friendly answers to various color science questions can be found
at
[https://www.rit.edu/cos/colorscience/rc_faq_all.php](https://www.rit.edu/cos/colorscience/rc_faq_all.php)

But really, books are better. There are a number of decent ones, e.g.
[http://amzn.com/047119459X](http://amzn.com/047119459X) or
[http://amzn.com/0470024259](http://amzn.com/0470024259) or
[http://amzn.com/1118173848](http://amzn.com/1118173848) or
[http://amzn.com/1568811616/](http://amzn.com/1568811616/) or the first half
of [http://amzn.com/1119967031](http://amzn.com/1119967031)

~~~
sago
I agree wholeheartedly. It goes from 'wavelength' to 'chromaticity and
intensity' to 'three dimensional cartesian coordinates' without explanation.
The 'color in one paragraph' paragraph would be incomprehensible if you didn't
already know all the missing steps, I felt.

And the need for diagrams: amen.

------
teddyh
There’s always the classic “Color space FAQ”:

[http://www.poynton.com/ColorFAQ.html](http://www.poynton.com/ColorFAQ.html)

------
TazeTSchnitzel
Relatedly: HSL and HSV's concept of brightness does not match that of the
human eye. HSL blue at 0.5 lightness is darker than HSL red at 0.5

------
IgorPartola
Well, now I need to recalibrate my monitors, except this time I will know what
I am doing. Thanks for the great article.

