UL 508A Industrial Control Panel Build
Ultimately, while regional variations exist, the only firm UL 508A wire color requirement is that grounds must be green.
UL 508A, specifically Section 17.3, states that insulated grounding and bonding conductors must be green (with or without yellow stripes). There's an exception for larger wires (4 AWG or larger) or those not manufactured in green, which can be identified with green markings at termination points.
One of the biggest myths is that the colors specified in Section 66 of UL508A must be followed. This is the downfall of cherry picking code, this section is only for Industrial Machinery which is a different label than UL 508A Industrial Control Panels which most people are building.