Repository navigation
Make Hair Color and Eye Color subclasses of Color. Make other requisite and appropriate revisions. #920
Description
I am exhuming a recommendation compiled from posts in #719 , which had been buried in the Discussion graveyard: Make Hair Color and Eye Color subclasses of Color.
I propose the following specific changes:
-
Give Hair Color this definition, along with the necessary subclassing: A Color that inheres in a Portion of Scalp Hair. [More on "Portion of Scalp Hair" below.]
-
Give Eye Color this definition, along with the necessary subclassing: A Color that inheres in an Iris. [Currently the definition holds that an Eye Color "inher[es] an Eye by virtue of the color of the Eye's Iris." I fail to see the motivation for this more complicated formulation.]
-
Give Scalp Hair this rdfs:label: Portion of Scalp Hair. [Maybe "Scalp Hair" can be an alt-label or pref-label.]
And while we're at it:
- Give Facial Hair this rdfs:label: Portion of Facial Hair. [Maybe "Facial Hair" can be an alt-label or pref-label.]
Metadata
Metadata
Assignees
Type
Projects
- Status
Activity
CarterBeauBenson commentedon Jul 9, 2026
I do not think they should be classes, personally. Otherwise, we should make "shirt color" and "logo color of a shirt" and "secondary logo color on a shirt".
Instead, there are just material entities and colors that inhere in them.
QuirkyQuark-101 commentedon Aug 17, 2026
I would tend to agree with Carter's assessment. Here are some additional thoughts to consider. (I will use informal terms as Im not familiar with CCO yet and do not currently possess the vocabulary you are familiar with.)
When thinking about subtype, I often ask how are the types different from each other in composition or behavior.
Eye color and hair color are not different types of color, but rather color observed from different objects. Practically speaking many data systems use labels such as eye color to shortcut the context from person ->eye color rather than person ->eyeball->iris->color. So it will appear on many schema models.
But that got me thinking about what would different types of color be?
Different in composition?
All color comes from light and the only variations have to do with wavelength, intensity, phase, and polarity.
We could distinguish mono color: "color perceived from a single wavelength", versus poly color : "color perceived by the combinations of different color wavelengths (RGB)"
OR
Different in behavior?
Color can be additive or subtractive. If the color is generated by the absorption of light it is subtractive (blue plus yellow equals green). But if the color is generated by a light source, it is additive ( blue plus green equals yellow).
It appears to me we have two different families of subtypes, mono vs poly and additive vs subtractive. What is the best way to handle this multiple kinds of subtype that are independent?