color-hash

Generate a color based on a value

This module generates a color based on an object, by calculating a color value based on a hash value for the object. This means the result is deterministic: the same value will always result in the same color (so long as the hash function remains deterministic).

This module is a port of the color-hash Javascript library.

It supports Python 3.7+ and it has no dependencies.

Quick Start

>>> from colorhash import ColorHash
>>> c = ColorHash('Hello World')
>>> c.hsl
(131, 0.65, 0.5)
>>> c.rgb
(45, 210, 75)
>>> c.hex
'#2dd24b'

Installation

Its hosted on PyPI.

pip install colorhash

Advanced usage

You can influence every aspect of final color. Default values are following:

ColorHash(
    obj: Any,
    lightness: Sequence[float, ...] = (0.35, 0.5, 0.65),  # picks 'randomly' one
    saturation: Sequence[float, ...] = (0.35, 0.5, 0.65),  # picks 'randomly' one
    min_h: Optional[int] = None,  # hue, min 0
    max_h: Optional[int] = None,  # hue, max 360
)

But be careful, setting tight conditions may result in very similar colors. See example tables.

You can fix lightness or saturation to single value(s) by using sequence with 1 element (eg. [0.5]).

code	hex	color
ColorHash('hey') # default	#782d86
ColorHash('hey', lightness=[0.55])	#b453c6
ColorHash('hey', lightness=[0.75])	#d69fdf
ColorHash('hey', lightness=[0.95])	#f7ecf9
ColorHash('hey', saturation=[0.15])	#8d6c93
ColorHash('hey', saturation=[0.55])	#b139c6
ColorHash('hey', saturation=[0.95])	#d406f9
ColorHash('hey', lightness=[0.95], saturation=[0.95])	#fbe6fe
ColorHash('oh', lightness=[0.95], saturation=[0.95])	#fef0e6
ColorHash('boi', lightness=[0.95], saturation=[0.95])	#e6fee7

You can set hue range or even fix it by setting min_h = max_h.

code	hex	color
ColorHash('hey', min_h=150)	#2d5886
ColorHash('hey', min_h=300)	#862d6c
ColorHash('hey', max_h=150)	#866e2d
ColorHash('hey', min_h=150, max_h=360)	#2d5886
ColorHash('hey', min_h=150, max_h=150) # fixed hue	#2d8659

Or you can let ColorHash decide between combination of many lightness and saturation options (mind min_h and max_h are equal in this example).

code	hex	color
ColorHash('stick', min_h=65, max_h=65, saturation=[x/10 for x in range(1, 10)], lightness=[x/10 for x in range(1, 10)])	#869108
ColorHash('with', min_h=65, max_h=65, saturation=[x/10 for x in range(1, 10)], lightness=[x/10 for x in range(1, 10)])	#eef5a3
ColorHash('one', min_h=65, max_h=65, saturation=[x/10 for x in range(1, 10)], lightness=[x/10 for x in range(1, 10)])	#ddeb47

Finally some bad examples. When you set too strict rules, colors may be almost identical.

code	hex	color
ColorHash('lets', lightness=[0.95], saturation=[0.95], min_h=300)	#fee6f8
ColorHash('break', lightness=[0.95], saturation=[0.95], min_h=300)	#fee6fb
ColorHash('it', lightness=[0.95], saturation=[0.95], min_h=300)	#fee6fa
ColorHash('here', min_h=150, max_h=150)	#6ce0a6
ColorHash('goes', min_h=150, max_h=150)	#79d2a6
ColorHash('almost', min_h=150, max_h=150)	#6ce0a6
ColorHash('same', min_h=150, max_h=150)	#79d2a6
ColorHash('color', min_h=150, max_h=150)	#6ce0a6

Changelog

• color-hash 2.0.0 (2023-09-22)
  • ✨ Expose params to influence colors
  • ✨ Runtime validation of input params
  • 📝 Update docs for advanced usage
• color-hash 1.3.2 (2023-09-21)
  • ⚡️ 30%+ speedup on hsl2rgb()
  • ✅ Add tests for all named colors (1500+ tests)
• color-hash 1.3.1 (2023-09-21)
  • 🐛 Handle missing importlib-metadata import
• color-hash 1.3.0 (2023-09-20)
  • 🧑‍💻 Add py.typed to support type annotations (#4)
  • 📦 Changed packaging ecosystem
    • ➖ Remove poetry
    • ➖ Remove tox
    • ➕ Add pip-tools (manage dependencies)
    • ➕ Add hatch (build & test)
    • ➕ Add twine (publish)
  • ✨ Support python3.11
  • ⚰️ Drop support for python3.6 (downloads from PyPI are under 1%)
• color-hash 1.2.2 (2022-10-17)
  • ✨ Add publish helper script
• color-hash 1.2.1 (2022-10-17)
  • 📝 Update docs
• color-hash 1.2.0 (2022-10-17)
  • 🧑‍💻 Use typing supporting python3.6
• color-hash 1.1.0 (2022-09-01)
  • ✅ Add tests
  • 🚸 Add installation instructions
• color-hash 1.0.4 (2021-11-30)
  • Support only for python3.6+
  • ✅ Add tests
• color-hash 1.0.3 (2020-12-04)
  • ⚰️ Drop support for python2.x
  • 🎉 Handover of project maintenance
• color-hash 1.0.2 (2016-07-08)
  • ✨ Add crc32_hash function and set default hashfunc to that. It's not fully backwards-compatible, but I don't want to bump the version a lot for not doing my research.
• color-hash 1.0.0 (2016-07-07)
  • 🎉 Initial port.

Speed comparison

Running pytest (1600+ tests) on different python versions.

python	secs
3.7	1.252
3.8	1.239
3.9	0.720
3.10	0.690
3.11	0.892

License

Copyright (c) 2016 Felix Krull [email protected]

This is a port of the 'color-hash' Javascript library which is:

Copyright (c) 2015 Zeno Zeng

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.