There are a few potential reasons why dyed purple hair can turn blue and green over time. When hair is dyed an unnatural color like purple, it requires a pigment deposit to overwrite the natural underlying pigment in the hair. Purple hair dye contains a mix of blue and red pigments. As the dyed color fades, the blue and red pigments can fade at different rates, causing the purple to take on more blue or red tones and appear blue, green, or muddy. The specific reasons purple dyed hair tends to turn blue/green include:
The science behind color fading
Hair dye works by depositing color pigment molecules into the hair shaft. These pigment molecules can be washed out and fade over time. Purple hair dye contains two main pigments:
- Blue pigment – Provides a blue tone to the color.
- Red/magenta pigment – Provides a red/pink tone to create purple.
When these two pigments fade at different rates, it alters the color balance and can make the purple take on more blue or green hues. Here’s why the pigments fade unevenly:
- Blue pigment molecules are larger and adhere better to the hair shaft.
- Red pigment molecules are smaller and wash out more quickly.
As the red fades faster, the blue is left behind, shifting the color towards blue and green shades. The bigger blue pigment sticks around longer.
Factors that contribute to fading
There are several factors that cause the color pigments to fade at different rates, resulting in purple turning blue/green:
1. Washing and water exposure
Frequent washing causes rapid fading as water rinses out the dye pigments. Red pigments in particular wash out quickly. Each wash removes more red pigment than blue.
2. Sun exposure
UV rays from the sun degrade hair dye pigments over time. Sunlight can especially fade red/magenta pigments rapidly.
3. Heat styling
Heat from blow drying, straightening, and curling tools accelerates fading. The heat causes pigment molecules to break down and wash out.
4. Pool/chlorine exposure
Chlorine from pools is extremely drying and damaging. It strips color pigments from the hair quickly. The red pigments tend to get stripped faster than blue.
5. Product build-up
Shampoos, conditioners, gels, and other products can coat the hair and block dye pigments from showing through. This build-up can make purple look muddy or greenish. Clarifying washes are needed.
How to prevent purple from turning blue/green
To keep purple hair vibrant for longer and prevent it from morphing into blue/green shades, follow these tips:
Wash less frequently
Wash hair only 1-2 times a week if possible, using sulfate-free shampoo to minimize fading.
Use cool water
Wash hair with the coolest water temperature you can stand. Hot water accelerates fading.
Apply gloss treatments
Use color depositing gloss to refresh the red/magenta tones and prevent purple from getting too blue.
Limit sun exposure
Wear a hat or use UV protecting products to limit sun damage to dyed hair.
Avoid chlorine
When swimming, wet hair first and apply conditioner to protect it from chlorine, then rinse promptly after getting out of the pool.
Clarify regularly
Use a clarifying shampoo once a week to remove product buildup that can make purple appear dull or greenish.
Use color protecting shampoo
Opt for professional shampoos for color treated hair, as these help lock in dye molecules and prolong vibrancy.
Get a gloss touch up
Have your colorist apply a semi-permanent gloss every 4-6 weeks to refresh the red pigment and prevent blue/green tones.
How to fix overly blue/green toned purple hair
If your purple hair has already become an undesired blue/green hue, here are some correction options:
Use a toner
Apply a magenta or red-violet toner on damp hair to neutralize green tones and add back warmth.
Try a color-depositing mask
Use a weekly conditioning color mask to deposit red pigments and counteract too much blue/green.
Get a color correction
See your colorist for a gloss service or partial highlight touch-up to rebalance your purple’s tone.
Do a full dye refresh
If toners and glosses aren’t enough, you may need to do a full redo of the purple color to get the right tone.
Maintaining vibrant purple hair long-term
To keep purple hair looking freshly dyed for as long as possible:
- Wash as infrequently as you can get away with.
- Rinse hair with cold water instead of hot.
- Apply a color-protecting shampoo and conditioner.
- Let hair air dry instead of heat styling.
- Limit direct sun exposure & chlorine contact.
- Use hydrating hair masks and oils to prevent dryness.
- Get regular gloss touch-up or semi-permanent color.
- Use toners if color balance gets off.
With the right maintenance routine, you can keep bold purple hair vibrant for months. But some fading and color shifts are inevitable. Embrace the color evolution and have fun switching up tones!
Conclusion
Purple hair turning blue or green is a common issue when dyeing hair unconventional colors. This color change happens because purple contains a mix of blue and red/magenta pigments that fade at different rates. The smaller red pigment molecules wash out quickly, while the larger blue pigment sticks around longer in the hair shaft. Factors like washing, sun, heat styling, and chlorine cause the red to fade rapidly, leaving behind more blue and green tones.
To prevent purple from morphing into muddy greens or blues, wash hair less often, use color-protecting products, limit damaging activities like swimming and heat styling, and get regular gloss or semi-permanent color touch-ups. If purple hair has already turned too blue/green, corrective toners, color masks, and professional color correction can help rebalance the tone. With proper maintenance, vibrant purple hair can be achieved long-term.
| Cause of Fading | Effect on Hair Color |
|---|---|
| Frequent washing | Removes more red pigment than blue |
| Sun exposure | Fades red pigments rapidly |
| Heat styling | Breaks down red molecules faster |
| Chlorine | Strips red pigments quickly |
| Product build-up | Blocks red tones from showing through |
