What should the colours of pushbutton heads typically represent ?
1. What you need to know
According to IEC 60204-1:2021, colors of pushbutton should not be chosen for aesthetic reasons. The purpose is to help operators to easily recognize the function of a pushbutton and act on the machine operation accordingly.
Green is the preferred color for START/ON function ; Red color can be used for STOP/OFF function if not close to an emergency stop device. Blue color can be used for RESET function. Yellow is preferred for ACK/INIT function.
For an emergency stop pushbutton, both IEC 60204-1:2021 and ISO 13850:2015 (Chapter 4.3) specify that the head must be red and the background shall be yellow. This color combination is exclusively reserved for emergency stop pushbuttons
2. Which standards define pushbutton color coding?
- IEC 60204-1 - Safety of machinery, Electrical equipment of machines. Clause 10.2.1. The primary reference for which color may be used for which actuator function on a machine.
- ISO 13850 - Emergency stop function. Chapter 4.3 Sets the red actuator on yellow background, the mushroom or palm shape, and the latching principle.
- NFPA 79 - Electrical Standard for Industrial Machinery applies to the US. NFPA 79 is aligned with IEC 60204-1 for pushbutton colors.
3. Pushbutton color matrix
| Function | Possible colors according to IEC 60204-1 | Preferred or commonly used color | Harmony XB4 - metal head ⌀22 |
|---|---|---|---|
| START/ON | WHITE, GREY, BLACK or GREEN | GREEN | Complete unit : XB4BA31 |
| STOP/OFF | BLACK, GREY, WHITE, or RED if not near to an emergency stop device | RED | Complete unit : XB4BA42 |
| RESET | BLUE, WHITE, GREY, or BLACK | BLUE | Complete unit : XB4BA61 |
| ACKNOWLEDGE or INIT (from abnormal state according to IEC60204-1) | YELLOW | YELLOW | Complete unit : XB4BA51 |
| EMERGENCY STOP | RED and YELLOW BACKGROUND | RED and YELLOW BACKGROUND | Complete unit : XB4BS8444 Complete control station with complete unit : XALK178F |
| OTHER FUNCTIONS | WHITE, GREY, or BLACK | BLACK or WHITE | Complete unit : XB4BA11 (WHITE) or XB4BA21 (BLACK) |
4. Schneider Electric references
| Type | Reference | Product description |
|---|---|---|
| Complete unit - GREEN | XB4BA31 | ⌀22 flush Pushbutton, spring return, green, metal, 1NO screw clamp terminals |
| Complete unit - RED | XB4BA42 | ⌀22 flush Pushbutton, spring return, red, metal, 1NC screw clamp terminals |
| Complete unit - BLUE | XB4BA61 | ⌀22 flush Pushbutton, spring return, blue, metal, 1NO screw clamp terminals |
| Complete unit - YELLOW | XB4BA51 | ⌀22 flush Pushbutton, spring return, yellow, metal, 1NO screw clamp terminals |
| Complete unit - WHITE | XB4BA11 | ⌀22 flush Pushbutton, spring return, white, metal, 1NO screw clamp terminals |
| Complete unit - BLACK | XB4BA21 | ⌀22 flush Pushbutton, spring return, black, metal, 1NO screw clamp terminals |
| Complete unit - EMERGENCY STOP | XB4BS8444 | Emergency stop switching off, metal, red mushroom 40mm, ⌀22,trigger turn to release, 2NC screw clamp terminals |
| Control station with EMERGENCY STOP | XALK178F | Control station, plastic, yellow lid, 1 red mushroom push button ⌀40, turn to release, 2NC screw clamp terminals |
Note1 : Those products are also available in plastic versions through XB5 range.
Note2 : Pushbuttons exist also in illuminated versions
Launch Product Selector on se.com to configure a Harmony selector switch according to your requirements or contact Schneider Electric Technical Support to check a configuration against your control scheme.