You're right about needing two 14/3 NM cables leaving the box with the initial 4-way switch.

Code Requirements and Best Practices Regarding Traveler Colors

The National Electrical Code (NEC) doesn't explicitly mandate specific colors for travelers in a 4-way switch circuit. However, it does address the general use of conductors and marking requirements, which inform best practices for traveler color coding.Here's a breakdown: NEC 200.7 (Use of White or Gray)

This section restricts the use of white or gray (or those with three continuous white stripes) wires for anything other than the neutral conductor. You cannot use white or gray for travelers.

NEC 200.7 (C)(1)

This section makes allowances for using a white or gray wire for the feed for the first 3-way switch. If this is the case, you MUST mark the wire to indicate that it is being used as a "hot" conductor. Black tape or marker works well to meet this code.

NEC 200.7 (C)(2)

This section makes allowances for using a white or gray wire for the feed for the switch leg. If this is the case, you MUST mark the wire to indicate that it is being used as a "hot" conductor. Black tape or marker works well to meet this code.

Good Practice (Consistency and Future Troubleshooting)

The primary reason to establish a color convention for travelers is for consistency and to aid in future troubleshooting. If someone opens the box years later, consistent color coding makes it much easier to understand the circuit.

Recommended Practice

Here's the most commonly recommended and safest approach:1. Never use white or gray

As stated above, these colors are reserved for neutrals and not for use as travelers.2.

Use Red and Black

This is a common and easy-to-follow convention. In the 14/3 cable: One traveler = Red wire The other traveler = Black wire Bare Copper = Ground

Therefore, the two travelers in each 14/3 cable should ideally be a red wire and a black wire.Why This Matters Safety

Consistent color coding reduces the risk of accidental shorts or mis-wiring during installation or maintenance.

Troubleshooting

Makes identifying and tracing wires much easier if there's ever a problem.

Professionalism

A well-wired, consistently color-coded job demonstrates professionalism and care.*

Future Modifications

If someone needs to add or modify the circuit later, consistent color coding makes the process much simpler and safer.

In summary, while the NEC doesn't dictate specific traveler colors beyond prohibiting white/gray, the best practice is to consistently use red and black for travelers throughout the 4-way switch circuit. I believe the vast majority of electricians will recommend this practice for the reasons stated above. Flag for review