POV-Ray : Newsgroups : povray.binaries.images : Stock colors and gamma : Re: Stock colors and gamma Server Time
3 Jul 2024 01:09:40 EDT (-0400)
  Re: Stock colors and gamma  
From: Alain
Date: 29 Nov 2014 20:22:36
Message: <547a715c@news.povray.org>

> As a rule, I don't use named colors in computer applications, because I am
> convinced that the bureaucrats who assign colors to names are colorblind.
> However, it seemed to me early on that something else was going on with the
> named colors in colors.inc.  Most of them seemed too pale, and many were
> entirely the wrong hue.
>
> About 2 years ago, I wrote a scene to plot the stock colors in a 3-D HSL
> structure, just to get an idea of how they were distributed.  After seeing all
> the colors at once, labeled, it occurred to me:  What if the colors were
> assigned using gamma 2.2 or sRGB?  After all, I had gotten the sense that
> assumed_gamma was a fairly new feature at the time I discovered POV-Ray, and it
> would seem reasonable that the colors were not assigned with linear rendering in
> mind.
>
> I have used assumed_gamma 1 in nearly all of my scenes since the day after I
> downloaded POV-Ray.  Literally.  (I checked.)  It's just something I don't even
> think about.  I re-rendered the scene with gamma 2.2, and the color assignments
> made a lot more sense.
>
> The other day, I wrote a scene to display the two versions of the stock colors
> side-by-side.  (Most of the grays are omitted.)  The scene uses assumed_gamma 1.
>   The left half of each test object uses the color straight from colors.inc.  On
> the right half, the sRGB transfer function is applied.
>
> Having solved this mystery, colors.inc is still not off the hook.  Coral, to me,
> is not a synonym for orange.  The Pink looks more like puce.  SlateBlue and
> MediumSlateBlue look far brighter than any slate I've witnessed, and I don't
> know what "steel blue" even means.  (Steel looks a neutral to warm gray to me.)
> Worst of all, the color named "Flesh" is /totally/ unrealistic.  DarkWood is
> much closer to the flesh color over most of my body, with my palms and soles
> between MediumWood and Feldspar depending on the computer monitor, the position
> of my hand, and the temperature of the room.
>
> P.S. The timing with A.D.B.'s post is pure coincidence.
>

Some of my personal gripes:
Maroon is much to red-purple. It's suposed to be a medium dark brown. 
The left part of "Very Dark Brown" is closer in shade, but a bit to 
dark, to the actual maroon nuts i get from the maroon tree from my backyard.
Salmon is supposed to be a palish shade of pink, but, some parts are darker.
New Midnight Blue is much to light and Midnight Blue looks under 
saturated. Using Navy Blue, right part, with a lowered diffuse would be 
beter.
For "Flesh", there are so many shades, from almost white to very dark 
browns, passing by the olivish, redish and yellowish shades and more. 
It's impossible to have one shade and realy be able to call it flesh 
without adding region, season, etnicity, darkness/lightness, ...
In my case, it may be somewhere between flesh, new tan and feldspar, 
with a small amount of pink added.


Post a reply to this message

Copyright 2003-2023 Persistence of Vision Raytracer Pty. Ltd.