PMS Colors
8 messages in this thread
I believe Corel Draw includes a file that gives a correspondence between PMS
colors and RGB values. It may not be straightforward, perhaps the RGB values
are given in 0.0 to 1.0 ranges, instead of 0 to 255. But I do remember seeing
an ASCII, readable file in the Corel distribution, as of about two years ago.
You might check any structured drawing programs you have… they might have a
swatch file that contains the approximations, too. Careful, though: PMS color
numbers are meant for printing, and once you try to go to RGB and then to your
monitor, you might not think they're the same color any more. Then add gamma
to the mixture, too…
>> I believe Corel Draw includes a file that gives a correspondence between PMS
colors and RGB values.
Thanks for the tip. I checked it out (Corel 3) and found some text files
(*.pan) that seem to be used to correct the colors for different output devices
like a Sony monitor or NEC monitor and different color printers. If I try to
use the CMYB converstion values in any of the files I get color that is not
even colose to what it should be. They are probably only used to shift/skew the
colors for that particular device. Good try though.
>> Careful, though: PMS color numbers are meant for printing…
Yes, I'm aware of that. I was hoping that someone had done an RGB conversion
chart using a color corrected monitor with correct gama. But, judging from the
files found in Corel, I would need to find a conversion chart that was done
specifically for a TARGA card. As Sam Becket would say 'Oooh Boy'.
As I said, thanks any how. Guess what I need to do is just get some PMS color
swatches and hold 'em next to the screen and tweek till I get it.
Scott.
What were the range of numbers in the .PAN files? If you type in a sample
line, I might have more advice. Second, you might try loading the swatch file,
then saving as an Adobe Illustrator file.
>> What were the range of numbers in the .PAN files?
Well, (deep subject, I know) the PMS 239 color (a green I think) is defined in
4 of the .PAN files as the following CMYK values:
CMYK150.PAN – 19,94,0,0
NECCMYK.PAN – 8,86,0,0
(these two seem to be for printers)
RGBMITSU.PAN – 0,54,13,22
RGBSONY.PAN – 0,59,12,27
(these two seem to be for monitors)
They all come out very un-green in Corel and PhotoStyler.
>> …try loading the swatch file, then saving as an Adobe Illustrator file.
Oh, good idea. Let's see if I follow. The 'swatch file' (if you mean a PMS
color swatch that I scanned in?) saved as an .AI file is actually an ASCII file
that would tell me the CMYK value of the swatch it discribes. Do I win? <g>
Ya know, I should do a little test while I'm at it. Display that scanned swatch
through 3DS on my TARGA card while holding the real thing next to the NTSC
screen to see how true the color remains after traveling though my system.
Humm, hope I dont have too much of an enlightening experience.
Scott.
If those are CMYK values, how are you translating them to RGB values? Do you
think they're 0..100 values? Or 0..255?
>> If those are CMYK values, how are you translating them to RGB values?
In Corel's color dialog you can select how you wish to enter your color
(RGB,CMYK, etc.).
>> They are percentage values (0-100).
This is out of one of the files:
; Format:
; 1) P PANTONE_ID Cyan_Value Magenta_Value Yellow_Value Black_Value
["PANTONE_Name"]
; Indicates a PANTONE INK where:
; PANTONE_ID – internal PANTONE ID number
; Cyan_Value – cyan percentage for this PANTONE color (0 – 100)
; Magenta_Value – magenta percentage for this PANTONE color (0 –
100)
; Yellow_Value – yellow percentage for this PANTONE color (0 – 100)
; Black_Value – black percentage for this PANTONE color (0 – 100)
; PANTONE_Name – optional PANTONE name string
Guess I could also save on all this guess work and just pop over to the COREL
forum and ask if there is a way to convert from PMS using this info. (what an
idea <g>).
Scott.
Once upon a time, I wrote the CYMK to RGB conversion for Harvard Draw aka
Harvard F/X, but I don't remember the details, and they didn't let me keep the
source code. 🙂
So you selected the PMS color, noted the equivalent RGB values, then entered
this value into 3DS, and it wasn't right?
Nope not even close. Like I said, I think these are some kind of correction
colors. I think my best bet (and most simple) is to get a PMS color swatch and
hold it next to the monitor till they match. (Brute force method). Thanks
anyhow for the help.
Scott.