Your mask has seven colours and the manual says almost nothing useful about any of them. Here's the practical version.
Red light — the one with the most research
Roughly 630–660nm. The longest wavelength in the visible range, which means it penetrates furthest into the skin.
This is the setting with the deepest body of published work behind it, generally looking at skin texture and firmness over a course of weeks. If you only ever use one colour, use this one.
Use it: as your default, three to five times a week.
Blue light — the surface one
Around 415nm. Short wavelength, stays near the surface, doesn't go deep.
Blue is the wavelength studied in the context of congested skin, where the research concerns its effect on surface bacteria rather than anything structural. It won't do what red does, and red won't do what blue does.
Use it: on weeks when your skin feels congested. Not as your everyday setting.
Purple — red and blue together
Exactly what it sounds like: both wavelengths at once. Convenient when you can't decide. Understand that you're splitting the output between two jobs rather than getting a third, stronger effect.
Yellow, green and cyan — the honest bit
These have considerably less published research behind them than red and blue. You'll find manufacturers making confident claims about each; the evidence is thinner than the marketing.
That doesn't make them useless — it means we're not going to tell you they do something specific when the research doesn't clearly show it. Use them if you like how they feel.
White — all of it at once
Every wavelength the device produces, simultaneously. The brightest setting by a distance. Keep your eyes closed.
A routine that makes sense
- Most sessions: red
- Congested skin: blue, for a week or two
- Can't decide: purple
- Winding down: whichever you find most pleasant — at that point you're choosing on comfort, and that's fine
Switching colours every single session is the most common mistake. Consistency with one wavelength beats rotating through all seven.
How to actually run a session
Clean, dry, bare skin — serum blocks the light. Ten to twenty minutes. Then go into your usual routine afterwards.
The Fask LED Mask cycles all seven from one button and covers the neck as well as the face, which most masks skip.
General information, not medical advice. If you take photosensitising medication, have a light-sensitive condition, or are pregnant, check with a healthcare professional first.