The meaning of "a stipple"

The definitions I found for this word was all art/drawing related.

Oxford dictionary: (in drawing, painting, and engraving) mark (a surface) with numerous small dots or specks.

Cambridge dictionary: to draw or paint something using small spots or marks

Which doesn't seems to apply in this context.

He’s wearing the uniform of the Guardians, but his cap is tilted at a jaunty angle and his sleeves are rolled to the elbow, showing his forearms, tanned but with a stipple of dark hairs.

Please provide me with a definition, thanks.

Collins sense 3b' is the relevant one:

stipple ... noun ...

• 3a. the art or method of painting, drawing, or engraving in dots [or 'marks', [CED; other dictionaries have 'flicks', 'flecks' or 'specks']
• 3b. the effect produced by this, or an effect, as in nature, resembling it

[italicising mine]