Where do colours start and end?

[Shaare]

Is there a science to determine where orange starts and end, in numbers?
Okay, so have colours been quantified. Orange in LAB can be from here to there?

 

[SteveSuffRIT]

The "science/math" is to use either the CIE hue angle (h') or the wavelength in nanometers (nm).
The bigger issue is the subjective/personal definition of "orange."
I would fan out the Pantone book and "find" your range of orange colors, then measure the start/first and end/last to get h' and nm.
I suspect the hue angle will be between 40'-80'?
Steve Suffoletto

 

[SteveSuffRIT]

After some further thaught, the hue angle range for orange may be more limited, 45'-65'

 

[SteveSuffRIT]

and by the way, Pantone Orange 021 has a hue angle h'= 52'.

 

[Shaare]

Hi Steve,

Thank you for replying. You see, I'm asking because I wrote a shareware swatchbook generator script for indesign for cmyk or mixedInk/cmyk+2 for the Iridesse. I want to write a ala Pantone Bridge version that'll span the rainbow however I wanted them in chapters, color-name based. Then it dawned on me that it was subjective so I wanted to check in and see if there was a standard, if colours had been formalized in numbers somewhere.

Thanks,

Antoine

ps: the script works on mac but you have to edit a file somewhere in the indesign program once.. google the error. On pc it works fine.

 

[SteveSuffRIT]

UNOFFICAL
Hue Angle - Color
345-41 Red
41-85 Orange
85-100 Yellow
100-205 Green
205-300 Blue
300-310 Violet
310-345 Purple
Source: Michael Pedersen in Copenhagen 2019

 

[smalloffsetpressexperts]

Orange your glad to find out

 

[Magnus59]

While on the subject of orange
I have a job to print on a digital press, either Indigo or Ricoh which is supposed to match a previous job we printed in spot colour Pantone 151 on offset
Sent to the Indigo 3550 with the Pantone colour preserved, the colour looked dull compared to the offset version, my initial thought - out of gamut colour

However, and this is where it gets interesting -

The colour produced from the Indigo is an acceptable match to a fairly new (less than 1 year old) Pantone book
I then pulled out my 15 year old Pantone book which is kept in my desk drawer
Pantone 151C is a perfect match to the offset job

Comparing the two books, 15 year old book - bright vibrant orange, new book dull lifeless orange
If it had been the other way round I would have put it down to my 15 year old book fading
Could it be the new book has been kept in less than optimal conditions - if so, why is the Indigo conversion matching the new book?

 

[cec-prepress]

Since you're comparing a new book and a 15 year old book, it is possible formulas changed. I know a few years ago Pantone switched to using L*A*B* values. For digital, it definitely makes a difference. A file sent to a digital press using PANTONE 151 C where the color is based on CMYK alternates (ex. a file created before Adobe updated their Pantone libraries) will print differently than the same file with PANTONE 151 C using the new L*A*B* values. In some cases, you can see a pretty big difference on screen.

 

[Magnus59]

Since you're comparing a new book and a 15 year old book, it is possible formulas changed. I know a few years ago Pantone switched to using L*A*B* values. For digital, it definitely makes a difference. A file sent to a digital press using PANTONE 151 C where the color is based on CMYK alternates (ex. a file created before Adobe updated their Pantone libraries) will print differently than the same file with PANTONE 151 C using the new L*A*B* values. In some cases, you can see a pretty big difference on screen.

I understand that the CMYK formulas change over time, but what I am seeing is a marked difference in the colours printed in the Pantone spot colour book, not in the Colorbridge or solid to CMYK swatches. The formula is 12 parts Pantone Yellow 4 Parts Pantone Warm Red, that hasn't changed and will never change.

 

[Glenn McDowall]

my fave (even tho' vermilion is missing)

The Color Strata – A Visualization Of XKCD's Color Name Data

www.datapointed.net