Aurora Colors Explained: Green, Red, Pink and Blue
Each aurora color is a fingerprint of a gas and a height. Once you know the pattern, a photo of the sky tells you a lot about what is happening above it.
Short answer: Green comes from oxygen about 60 to 150 miles up and is the most common aurora color. Red comes from oxygen higher up, above roughly 150 miles. Pink, purple and blue come mostly from nitrogen, usually at the lower edge of bright displays.
Green: the most common color
Most aurora is green. The light comes from oxygen atoms at about 60 to 150 miles (100 to 240 km) up, at a wavelength of 557.7 nanometers.
Two things make green so common. Oxygen at that height is plentiful, and the human eye is most sensitive to green-yellow light. So even a modest display tends to look green, at least on camera.
Red aurora: high and slow
Red aurora also comes from oxygen, but from much higher, roughly 150 to 250 miles (240 to 400 km) up. Its wavelength is 630 nanometers.
An excited oxygen atom needs close to two minutes to give off red light. Lower down, it would bump into other particles before that and lose the energy without glowing. Only in the very thin air at great heights can it wait long enough. That is why red sits on top of green curtains.
The eye is weak at seeing dim red light. Red aurora often shows clearly in photos while looking faint or colorless in person.
Why red aurora shows at low latitudes
People far from the poles often see red first, or only red. There are two main reasons.
- Height and geometry. Red light comes from the top of the aurora. Because it is so high, it can be seen above the horizon from hundreds of miles farther away than the green below it.
- Big storms. During strong geomagnetic storms, more low-energy electrons reach the upper atmosphere and boost the high red glow. A related feature, the stable auroral red arc, can also appear at mid-latitudes.
During the G5 storm of May 10-11, 2024, many photos from the southern US showed deep red and magenta skies. Learn more in how far south you can see the northern lights.
Pink and purple: the lower edge
Bright, active curtains sometimes have a pink or magenta fringe along the bottom. This comes from nitrogen molecules at about 50 to 60 miles (80 to 100 km) up, struck by high-energy particles that reach deeper into the air.
Purple and violet can also appear when blue nitrogen light mixes with red oxygen light. A pink lower edge usually means the display is strong and active.
Blue and violet aurora
Blue and violet come from ionized nitrogen molecules. This light is often hidden by brighter green, and the eye is not very sensitive to it at night.
Blue aurora is sometimes seen at the top of tall rays that reach into sunlit air high above the night side of Earth. Sunlight can boost the nitrogen glow there, giving the rays a blue or purple tip.
Quick color guide
| Color | Gas | Approximate height | How often |
|---|---|---|---|
| Green | Oxygen | 60-150 miles | Most displays |
| Red | Oxygen | 150-250 miles | Tops of displays, big storms |
| Pink, magenta | Nitrogen | 50-60 miles | Lower edge of bright displays |
| Blue, violet | Nitrogen | Varies | Less common, often faint |
Heights are approximate. For the full story of how particles reach these layers, read what causes the northern lights.
Questions people ask
What is the rarest aurora color?
Blue and violet are the hardest to see, because they are faint and the eye is not sensitive to them in the dark. Deep red overhead is also uncommon outside of strong storms.
Is red aurora a sign of a strong storm?
At mid and low latitudes, red aurora often goes with strong geomagnetic storms. Near the poles, red tops on green curtains are more routine.
Why does the aurora look white to me but green in photos?
In dim light the eye uses rod cells, which do not see color well. A camera collects light over several seconds and records the real color.
Is a pink glow always aurora?
Not always. Light pollution, airglow and a feature called STEVE can also tint the night sky. See our guide on aurora vs airglow and STEVE.
Written by the aurorahour team from published science and NOAA data. General information, not a promise of any display. Last checked: October 2026.