Is there a spec for RGB values of the emoji skin tone modifiers?

Question

Wikipedia and Unicode.org both illustrate the emoji skin tone modifiers.

Where are the RGB values specified? (Surely this can't be the font designer's arbitrary choice... there must be a reference somewhere that shows it.)

Answer 1

Read Emoji Modifier Sequence at https://emojipedia.org/:

Emoji characters can be modified to use one of five different skin tone modifiers. Each tone is based on the Fitzpatrick Scale.

The Fitzpatrick Skin Type Classification system was developed in 1975 by Harvard Medical School dermatologist Thomas Fitzpatrick, MD, PhD. This system classifies complexions and their tolerance of sunlight…

Read the Fitzpatrick skin phototype document as well…

Edit

Fitzpatrick Scale / Von Luschan’s Chromatic Scale

The Von Luschan’s Scale was developed as a tool to assess racial classifications according to skin color. It consists of 36 colored tiles which are compared to a person’s skin color.

This image is a reproduction of the Von Luschan scale which was originally created by Felix von Luschan and printed in Voelker, Rassen, Sprachen (1927). The original chart was scanned and the skin colors were copied using the paint program’s dropper tool.

Our team at Open Oximetry calculated the RBG values which are superimposed on the image of the scale. Notably, 13 and 14 were found to have the same RGB values.

Note 1: get your own values:

Take any image of von Luschan scale (or Fitzpatrick one), open it in an image editor (e.g. as simple as Windows' native mspaint.exe), use the Colour Picker tool to get the RGB values:

or get them programmatically: How to read the RGB value of a given pixel in Python?…

Note 2: Caution! There are different ways of converting the 36 categories of the von Luschan scale to the six categories of the Fitzpatrick scale (example in PowerShell):

$Fitzpatrick = @'
Type;Effect of Light Exposure;Description;Von Luschan’s Description;Von Luschan’s Color
I;Always burns, never tans;Pale, fair, freckles;Very light;1-5
II;Usually burns, sometimes tans;Fair;Light;6-10
III;May burn, usually tans;Light brown;Intermediate;11-15
IV;Rarely burns, always tans;Olive brown;Mediterranean;16-21
V;Moderate constitutional pigmentation;Brown;Dark or brown;22-28
VI;Marked constitutional pigmentation;Black;Very dark or black;29-36
'@ | ConvertFrom-Csv -Delimiter ';'
$Fitzpatrick | Select-Object -Property (
    "Type","Von Luschan’s Color","Von Luschan’s Description") |
        Out-Default
<#

(based on TABLE V.—Skin Classification by Pigmentation (page 21) in Imaging skin: Past, present and future perspectives by Marty O. Visscher)

<##>

$FitzpatrickWiki = @'
Type;von Luschan scale;Also called
I;0–6;Very light or white, "Celtic" type[5]
II;7–13;Light or light-skinned European[5]
III;14–20;Light intermediate, or dark-skinned European[5]
IV;21–27;Dark intermediate or "olive skin"[5]
V;28–34;Dark or "brown" type
VI;35–36;Very dark or "black" type
'@ | ConvertFrom-Csv -Delimiter ";"
$FitzpatrickWiki | Out-Default
<#

(based on this Wikipedia table: the 36 categories of the von Luschan scale in relation to the six categories of the Fitzpatrick scale in Von Luschan's chromatic scale)

<##>

Result: \SO\75489304.ps1

Type Von Luschan’s Color Von Luschan’s Description
---- ------------------- -------------------------
I    1-5                 Very light
II   6-10                Light
III  11-15               Intermediate
IV   16-21               Mediterranean
V    22-28               Dark or brown
VI   29-36               Very dark or black



Type von Luschan scale Also called
---- ----------------- -----------
I    0–6               Very light or white, "Celtic" type[5]
II   7–13              Light or light-skinned European[5]
III  14–20             Light intermediate, or dark-skinned European[5]
IV   21–27             Dark intermediate or "olive skin"[5]
V    28–34             Dark or "brown" type
VI   35–36             Very dark or "black" type