From owner-freebsd-questions@freebsd.org  Wed Dec 30 16:40:23 2015
Return-Path: <owner-freebsd-questions@freebsd.org>
Delivered-To: freebsd-questions@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id 31B1AA55C2C
 for <freebsd-questions@mailman.ysv.freebsd.org>;
 Wed, 30 Dec 2015 16:40:23 +0000 (UTC)
 (envelope-from smithi@nimnet.asn.au)
Received: from sola.nimnet.asn.au (paqi.nimnet.asn.au [115.70.110.159])
 (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id AF79F1FF5
 for <freebsd-questions@freebsd.org>; Wed, 30 Dec 2015 16:40:22 +0000 (UTC)
 (envelope-from smithi@nimnet.asn.au)
Received: from localhost (localhost [127.0.0.1])
 by sola.nimnet.asn.au (8.14.2/8.14.2) with ESMTP id tBUGeJWr012325;
 Thu, 31 Dec 2015 03:40:19 +1100 (EST)
 (envelope-from smithi@nimnet.asn.au)
Date: Thu, 31 Dec 2015 03:40:18 +1100 (EST)
From: Ian Smith <smithi@nimnet.asn.au>
To: Warren Block <wblock@wonkity.com>
cc: Roland Smith <rsmith@xs4all.nl>, freebsd-questions@freebsd.org
Subject: [solved] [OT] Light frequency or wavelength to (eg RGB) colour
In-Reply-To: <alpine.BSF.2.20.1512300846440.68347@wonkity.com>
Message-ID: <20151231033050.R8562@sola.nimnet.asn.au>
References: <20151231012759.I8562@sola.nimnet.asn.au>
 <alpine.BSF.2.20.1512300846440.68347@wonkity.com>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.20
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-questions>, 
 <mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions/>
List-Post: <mailto:freebsd-questions@freebsd.org>
List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
 <mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 30 Dec 2015 16:40:23 -0000

On Wed, 30 Dec 2015 08:49:41 -0700, Warren Block wrote:
 > On Thu, 31 Dec 2015, Ian Smith wrote:
 > 
 > > does anyone know of a method - preferably a formula - for converting
 > > known frequencies (or complementarily, their wavelengths) within the
 > > visible spectrum to its colour rendition in RGB, CMYK or whatever?
 > 
 > http://stackoverflow.com/questions/1472514/convert-light-frequency-to-rgb
 > 
 > The first answer supplies as many formulas as anyone might want.  Scroll down
 > and there is a Pascal routine to actually do the conversion.

Thanks Warren .. indeed that leads into quite a number of rabbit holes.

Thanks also to Roland Smith who sent me offlist (due to OT :) a link to 
his neat rendition in Python from apparently the same Pascal code:

https://github.com/rsmith-nl/wavelength_to_rgb

Thanks again folks; much easier than I thought this was going to be.

cheers, Ian