What are some safe paint types for use in medical devices?

Metallic craft glitter should not be used for face painting.
The only safe glitters for face painting are made of polyester, and should be .008 microns in size or smaller.
That is the size that the FDA classifies as “cosmetic size” and safe for use on skin.

In general, a safe coating for medical devices is Polymer, to be more specific; polyester, A low-gloss polyurethane, Polytetrafluoroethylene(PTFE)....etc Those coatings contain chemicals to achieve the desired properties of color, water and mildew resistance, antimicrobial and flame retardancy.
whereas, there is no generally recognized as safe paints, exemption to the definition of a color additive.
Under certain conditions, color additives in medical devices are subject to the same provisions that apply to color additives in foods, drugs and cosmetics.
Those color additives such as: Erythrosine, Amaranth, triphenylmethane, Canthaxanthin, synthetic zeaxanthin & astaxanthin are considered as authorized color agents for medical devices.
Even the above color additives used in medical devices must comply with individual listing regulations.
In USA, FDA conducts a certification program for batches of color additives that are required to be certified, including product labeling.
Each listed color additive, provide chemical specifications for the color additives, and identify uses and restrictions, labeling requirements and the requirement for certification.
For example: {{{Straight Color: D&C Blue No.9 / Uses and Restrictions: Cotton and silk surgical sutures; NTE2.5% general and ophthalmic use.}}} FDA Act limits applicability of these provisions to color additives that directly contact the body for a significant period of time.
At the present time, the term a "significant period of time" is not defined by FDA regulation.