At least on my distribution (Currently Slackware 7, soon to be Debian,
long story)
man X (note the uppercase X)
gives lots of useful info.
If you search for 'color', it should answer your question in extreme
detail and precision.
The rest of the message is cut-n-pasted from there...
A numerical color specification consists of a color space
name and a set of values in the following syntax:
<color_space_name>:<value>/.../<value>
An RGB Device specification is identified by the prefix
"rgb:" and has the following syntax:
rgb:<red>/<green>/<blue>
<red>, <green>, <blue> := h | hh | hhh | hhhh
h := single hexadecimal digits
Note that h indicates the value scaled in 4 bits, hh the
value scaled in 8 bits, hhh the value scaled in 12 bits,
and hhhh the value scaled in 16 bits, respectively. These
values are passed directly to the X server, and are
assumed to be gamma corrected.
The eight primary colors can be represented as:
black rgb:0/0/0
red rgb:ffff/0/0
green rgb:0/ffff/0
blue rgb:0/0/ffff
yellow rgb:ffff/ffff/0
magenta rgb:ffff/0/ffff
cyan rgb:0/ffff/ffff
white rgb:ffff/ffff/ffff
For backward compatibility, an older syntax for RGB Device
is supported, but its continued use is not encouraged.
The syntax is an initial sharp sign character followed by
a numeric specification, in one of the following formats:
#RGB (4 bits each)
#RRGGBB (8 bits each)
#RRRGGGBBB (12 bits each)
#RRRRGGGGBBBB (16 bits each)
The R, G, and B represent single hexadecimal digits. When
fewer than 16 bits each are specified, they represent the
most-significant bits of the value (unlike the "rgb:" syn-
tax, in which values are scaled). For example, #3a7 is
the same as #3000a0007000.
An RGB intensity specification is identified by the prefix
"rgbi:" and has the following syntax:
rgbi:<red>/<green>/<blue>
The red, green, and blue are floating point values between
0.0 and 1.0, inclusive. They represent linear intensity
values, with 1.0 indicating full intensity, 0.5 half
intensity, and so on. These values will be gamma cor-
rected by Xlib before being sent to the X server. The
input format for these values is an optional sign, a
string of numbers possibly containing a decimal point, and
an optional exponent field containing an E or e followed
by a possibly signed integer string.
On Wed, 10 May 2000, Annelise Anderson wrote:
| I think blackbox is wonderful.
|
| I'm trying to get more contrast in a style with solid colors
|(I started with steelblue) and I'd like to know where I can find out
|the meanings of things like rgb:5/78/a and rgb:4/6/8. I can get
|something from just experimenting but a reference would be good.
|I want some screen shots (not in color) that print well.
|
| I read quite a lot of the web page material and didn't find
|anything, but it certainly is beautifully done!
|
| Sorry if I missed it.
|
| Annelise
|
--
=========================================================================
Robert Thompson <[EMAIL PROTECTED]> Southwestern Adventist University
"My opinions are my own. Want one?" Department of Computer Science
