Pushbutton operating parts must be color-coded in accordance with the
following table that discusses color coding for pushbutton actuators and the meanings of the colors.
- The preferred colors for START/ON parts should be WHITE, GREY or BLACK, preferably WHITE. GREEN may be used; RED must not be used. The color RED must be used for emergency-off actuators.
- The colors for STOP/OFF actuators should be BLACK, GREY or WHITE, preferably BLACK. RED is likewise permissible. GREEN must not be used.
- WHITE, GREY and BLACK are the preferred colors for push-button actuators which function alternately as START/ON and STOP/OFF pushbuttons. The colors RED, YELLOW or GREEN must not be used.
- WHITE, GREY and BLACK are the preferred colors for push-button actuators which effect an operation whilst they are actuated and terminate
- operation when they are released (e.g. jogging). The colors RED, YELLOW and GREEN must not be used.
- The color GREEN is reserved for functions indicating a safe or normal operation. The color YELLOW is reserved for functions indicating a warning or abnormal status. The color BLUE is reserved for functions of urgent significance.
- Reset push-buttons must be BLUE, WHITE, GREY or BLACK. If these are also used as STOP/OFF buttons, the colors WHITE, GREY or BLACK are preferred, preferably BLACK. GREEN must not be used.
It is advisable to label pushbuttons with symbols, either adjacent to or preferably directly on the actuator, in accordance with the following table:
Source: Rittal’s “Technical Aspects of Enclosures” Handbook