While several OSHA regulations dictate that permanent aisles and passageways must be clearly marked, there are no current government-mandated or even widely accepted industry standards that recommend what colors to use when marking floors.
However, when it comes to workplace visuals there are a number of relevant standards that require or imply the need for marking and color-coding:
Occupational Safety and Health Administration (OSHA) Floor Marking Guidelines
Use of Mechanical Equipment
§1910.176(a) Where mechanical handling equipment is used, sufficient safe clearances shall be allowed for aisles, at loading docks, through doorways and wherever turns or passage must be made. Aisles and passageways shall be kept clear and in good repair, with no obstruction across or in aisles that could create a hazard. Permanent aisles and passageways shall be appropriately marked.
General Environmental Controls
§1910.144 Red shall be the basic color for the identification of fire protection equipment and apparatus, containers of flammable liquids, stop buttons and electrical switches used for emergency stopping of equipment.
§1910.144(a)(1) Red shall be the basic color for the identification of fire protection equipment and apparatus.
§1910.144(a)(3) Yellow shall be the basic color for designating caution and marking physical hazards.
Means of Egress
§1910.35 OSHA will deem an employer demonstrating compliance with the exit route provisions of NFPA 101, Life Safety Code, or the exit-route provisions of the International Fire Code (IFC), 2009 edition, to be in compliance with §1910.34, §1910.36 and §1910.37.
Letter of Interpretation
§1910.22(b) The lines used to delineate aisles may be any color so long as they clearly define the area considered as aisle space. The lines may be composed of dots, square, strip or continuous. The recommended width of aisle markings varies from 2 in. to 6 in., therefore any width 2 in. or more is considered acceptable.
International Fire Code 2009
§1024.1 Approved luminous egress path markings delineating the exit path shall be provided...having occupied floors located more than 75 ft. above the lowest level of fire department vehicle access.
§1024.2.1 A solid and continuous stripe shall be applied to the horizontal leading edge of each step and shall extend the full length of each step.
§1024.2.4 Perimeter and floor mounted demarcation lines shall be placed within 4 in. of the wall and extend to within 2 in. of the markings on the leading edge of landings. Demarcation lines shall be 1 in. to 2 in. wide with interruptions not exceeding 4 in.
Additional relevant standards
When it comes to workplace visuals, there are a number of relevant standards that require or imply the need for marking and color-coding:
ANSI color guide — safety signage
Some experts reference the ANSI Z535.1 Safety Color Code standard as a guide for floor marking. While earlier versions of the standard (ANSI Z353.1-1998) did include color specifications for specific types of safety hazards and equipment, these specifications were removed from the 2002 edition of the standard and no longer represent ANSI recommended best practices. Section 4.2 of the standard explicitly states that the specifications are intended for use on safety signage, not for floor marking.
OSHA color guide — hazards
Some experts also reference OSHA standard 29 CFR 1910.144, the Safety Color Code for Marking Physical Hazards. However, these specifications are extremely limited in scope and are not designed to provide guidance on color usage when marking floors either. The standard states that red should be used to identify fire protection equipment, emergency stop devices and containers holding dangerous materials. Yellow should be used for marking physical hazards (such as striking against, stumbling, falling, tripping and caught-in-between hazards).