Helmgen

The Helmgen color space is not registered in Color by default

Properties

Name: helmgen

White Point: D65 / 2˚ (Variant from ASTM-E308)

Coordinates:

Name	Range^*
`l`	[0, 1.0]
`a`	[-0.6, 0.6]
`b`	[-0.6, 0.6]

^* Space is not bound to the range and is only used as a reference to define percentage inputs/outputs.

Helmlab is a family of purpose-built color spaces, two to be exact. The first is the Helmlab Metric space which is designed for perceptual distance measurements, claiming STRESS 23.30 on COMBVD - 20% better than CIEDE2000. The second is the Helmgen space which is designed for gradient and palette generation (60-8 vs Oklab on ColorBench's 83 metrics, 360/360/360 gamut cusps, zero monotonicity violations).

Helmgen is the generation-optimized space and is specifically used for interpolation, palettes, etc. It is the general purpose color space of the Helmlab family.

Learn more.

Channel Aliases

Channels	Aliases
`l`	`lightness`
`a`
`b`

Inputs

The Helmgen space is not currently supported in the CSS spec, the parsed input and string output formats use the color() function format using the custom name --helmgen:

color(--helmgen l a b / a)  // Color function

The string representation of the color object and the default string output use the color(--helmgen l a b / a) form.

>>> Color("helmgen", [0.56321, 0.29471, 0.18551])
color(--helmgen 0.56321 0.29471 0.18551 / 1)
>>> Color("helmgen", [0.75771, 0.07633, 0.24769]).to_string()
'color(--helmgen 0.75771 0.07633 0.24769)'

Registering

from coloraide import Color as Base
from coloraide.spaces.helmgen import Helmgen

class Color(Base): ...

Color.register(Helmgen())