Front fog light indicator
The front fog lamps are switched on. UN R121 makes this tell-tale green; FMVSS 101 does not list it.
Green
What to do
Nothing is wrong. Switch the front fog lamps off when visibility is good; local traffic rules set when they may be used.
Makes differ: what this light means on your car, the other colours it may use for the symbol and what the car wants you to do are set by the manufacturer, so your car's owner's manual is the authority.
- Symbol
- Lamp facing left, slanted beams, wavy line
- Colour
- Green
What the colour means
Green — “safety”
The colour code gives “green: safety” (Directive 2009/80/EC, Annex I, 2.1.4). In both tables green marks lamps that are simply switched on — turn signals, dipped beam, position lamps — and FMVSS 101 also allows it for the high-beam telltale.
Where the regulations list it
| Rule | Row | Colour it sets |
|---|---|---|
| UN R121 | Table, item 7 “Front fog lamps” — tell-tale | green |
UN R121: Cars (category M) and light goods vehicles (N1) type-approved under the UN 1958 Agreement, which includes the EU, UK and Japan (para 1). Its table gives the symbol and colour of each tell-tale; note 2 says the symbols are substantially identical to those of ISO 2575:2004.
Good to know
- Tell the two fog symbols apart by the beams: lines slanting down for the front lamps (green), straight lines for the rear lamp (yellow).
Other green lights
Sources
- EUR-Lex — UN Regulation No. 121 (01 series), Official Journal of the EU L 5, 8 January 2016: table 'Symbols, their illumination and colours' — checked 2026-09-23
- Directive 2009/80/EC, Annex I, point 2.1.4 — the tell-tale colour meanings as written into EU law (for two- and three-wheel vehicles) — checked 2026-09-23
Meanings are written in our own words from these public texts, not quoted from ISO 2575, and were checked on the date shown.