102 lines
4.2 KiB
Plaintext
102 lines
4.2 KiB
Plaintext
This directory contains several alternative rgb databases:
|
|
|
|
old-rgb.txt the version that was shipped in previous
|
|
releases; this was originally "tuned" for
|
|
the Digital VT240 series terminals.
|
|
|
|
raveling.txt lots of new colors, tuned by Paul Raveling
|
|
at ISI for the HP monitor; see below.
|
|
|
|
thomas.txt a version of the older database that was
|
|
tuned by John Thomas at Tektronix to match
|
|
a box of Crayola crayons; see below.
|
|
|
|
|
|
Notes from Paul Raveling:
|
|
|
|
1. Many colors have been tuned for an HP monitor -- mine,
|
|
to be exact. Some of the old values were obnoxious enough
|
|
to bring complaints from users (like "That's Wheat???!!!");
|
|
so far early user reports on the new RGB database are favorable.
|
|
|
|
2. File rgb.txt was reorganized into 3 sections:
|
|
|
|
a) Light and off-white colors, copied from several Sinclair
|
|
Paints color samples. The intent for adding these is
|
|
to provide a better choice for light-colored window
|
|
backgrounds.
|
|
|
|
BTW, I wanted to find ANSI standard colors, but ANSI
|
|
happily gobbled my $16 without sending the specification
|
|
I ordered, Then they ignored my followup letter.
|
|
Nuts to ANSI & "ANSI standards".
|
|
|
|
b) Special colors such as black, white, and favorite
|
|
shades of gray.
|
|
|
|
c) A spectrum of colors, arranged to transition gradually
|
|
between nearby colors, running from generally blue
|
|
colors through green and ending with generally red colors.
|
|
This includes all colors from the old X11R3 database,
|
|
but they're no longer in (mostly) alphabetic order.
|
|
|
|
d) The gray scale from the original X11R3 database.
|
|
|
|
|
|
Within the "spectrum of colors" section there are clusters
|
|
of colors, each consisting of:
|
|
|
|
1. One or more Specially named colors. If more than one
|
|
is present, all are related by lying on a common line
|
|
running from RGB = (0 0 0) [pure black] to a single
|
|
point on the surface of the RGB color cube.
|
|
|
|
2. Four colors at particular points on the same line in
|
|
RGB space. Their names end in "1", "2", "3", and "4",
|
|
with "color1" being at the surface of the color cube
|
|
and the others at increasing distances approaching black.
|
|
Distance of these color points from black is approximately
|
|
logarithmic. This attempts a rough fit to human
|
|
perception's sensitivity to intensity.
|
|
|
|
Here's an example of one of these clusters:
|
|
|
|
210 105 30 chocolate
|
|
139 69 19 saddle brown
|
|
139 69 19 SaddleBrown
|
|
255 127 36 Chocolate1
|
|
238 118 33 Chocolate2
|
|
205 102 29 Chocolate3
|
|
139 69 19 Chocolate4
|
|
|
|
Note that the "original" colors, in this case chocolate
|
|
and saddle brown, don't always match the scaled points.
|
|
|
|
|
|
Does anyone think these changes are a good idea? Crummy idea?
|
|
Do you have other favorite colors? Can anyone do better at
|
|
matching some tough colors? Some colors, especially reddish
|
|
ones, were VERY hard to reproduce, & I'd welcome contributions
|
|
from other HP users who can get a better match.
|
|
|
|
|
|
|
|
Notes from John Thomas:
|
|
|
|
Advised by our human factors folks that "standard" named colors exist, but
|
|
only for well-controlled color coordinate systems (like CIE, but not for RGB),
|
|
I sat down one evening with the handiest standard of subjective color names,
|
|
a box of 72 Crayola crayons. (Believe it or not, over 50% of the colors from
|
|
rgb.txt were represented.)
|
|
|
|
Using an X-client implementation of the TekColor model, I created the following
|
|
list of named colors. Appearance on your monitor may vary because of brand,
|
|
age, and video drive circuitry, but I think you will find it a better match
|
|
for the average monitor, than the original rgb.txt file from MIT.
|
|
|
|
|
|
John C Thomas
|
|
Tektronix, Inc.
|
|
Wilsonville, OR
|
|
jct@windex.TEK.COM
|