Does the entire guard, or just a small portion, need to be color-coded?

Section 29 CFR 1910.144(a)(3) states that yellow shall be the color for marking physical hazards, but it does not specify where and how much of a machine or physical hazard needs to be marked. Being a performance-oriented standard, this is left to the discretion of the employer to determine first, the necessity of color-coding, and second, the optimum location and extent of the markings. To reiterate what the standard says, “Yellow is used to identify physical hazards.” If the guard of a machine does not present a physical hazard such as, but not limited to, tripping, falling, struck by, or caught-between, then there would be no need for color-coding.