Swatch

swatch is a parser for adobe swatch exchange files

Copyright (c) 2014 Marcos A Ojeda http://generic.cx/

With help from ASE documentation written by Carl Camera and the ase generator written for colourlovers by Chris Williams

swatch.write(lst, filename) reads in a list, as described below and outputs a .ase file. (new in v0.4.0)

swatch.parse(filename) reads in an ase file and converts it to a list of colors and palettes. colors are simple dicts of the form:

{
    'name': u'color name',
    'type': u'Process',
    'data': {
        'mode': u'RGB',
        'values': [1.0, 1.0, 1.0]
    }
}

the values provided vary between color mode. For all color modes, the value is always a list of floats.

RGB: three floats between [0,1] corresponding to RGB. CMYK: four floats between [0,1] inclusive, corresponding to CMYK. Gray: one float between [0,1] with 1 being white, 0 being black. LAB: three floats. The first L, is ranged from 0,1. Both A and B are floats ranging from [-128.0,127.0]. I believe illustrator just crops these to whole values, though.

Palettes (Color Groups in Adobe Parlance) are also dicts, but they have an attribute named swatches which contains a list of colors contained within the palette.:

{
    'name': u'accent colors',
    'type': u'Color Group',
    'swatches': [
        {color}, {color}, ..., {color}
    ]
}

Because Adobe Illustrator lets swatches exist either inside and outside of palettes, the output of swatch.parse is a list that may contain swatches and palettes, i.e. [ swatch* palette* ]

Here's an example with a light grey swatch followed by a color group containing three swatches:

>>> import swatch
>>> swatch.parse("example.ase")
[{'data': {'mode': u'Gray', 'values': [0.75]},
  'name': u'Light Grey',
  'type': u'Process'},
 {'name': u'Accent Colors',
  'swatches': [{'data': {'mode': u'CMYK',
     'values': [0.5279774069786072,
      0.24386966228485107,
      1.0,
      0.04303044080734253]},
    'name': u'Green',
    'type': u'Process'},
   {'data': {'mode': u'CMYK',
     'values': [0.6261844635009766,
      0.5890134572982788,
      3.051804378628731e-05,
      3.051804378628731e-05]},
    'name': u'Violet Process Global',
    'type': u'Global'},
   {'data': {'mode': u'LAB', 'values': [0.6000000238418579, -35.0, -5.0]},
    'name': u'Cyan Spot (global)',
    'type': u'Spot'}],
  'type': u'Color Group'}]

Spot, Global and Process

Something that's not mentioned in either carl camera's or chris william's code is the mention of spot, global and process colors.

There are three kinds of swatch types available to you in a ASE files: Process, Global and Spot. Process colors are standard colors, this is the default if you define a new color in illustrator. As the name implies, they're mixed from either RGB or CMYK depending on the document color mode.

Global colors are the same thing as process colors, but they have one neat property which is that when you update them, they are updated all throughout your artwork. This makes them something like "color references" and quite useful if you're doing something like reskinning some extant document.

Spot colors are implicitly global but have the nifty property that you can create new swatches from them based on "tints" or, effectively some screened value of that color. The only hitch is that tints, even though they can be part of your file, can't be stored/exchanged as swatches. I'm on the fence as to how problematic this is, but that's just how it goes. Even illustrator won't save them out, it's just not supported in the app (almost certainly due to the nature of the file format)

Caveats

Finally, consider the fact that your swatches can be CMYK a mixed blessing. While this is invariably useful if you need to import some old swatches for print work, it will pose a challenge for accurately converting back to RGB/LAB unless you have a copy of illustrator handy.

If you don't, you can always install color profile calculator in the (oddly named) little cms and feed it the freely available SWOP icc color profile and use the default output of sRGB to get your colors in a somewhat usable form for the web.

If you end up with LAB spot colors, you can always pay Bruce Lindbloom a visit to get the relatively easy, if somewhat time consuming, LAB->XYZ->RGB formulas.