What do the numbers mean on Hair Dye?

[Anonymous]

I've seen multiple hair dye brands with different numbers, i. e. 7, 5.3, 8.2, 465, 80, 73, 70.

What is the difference between the higher and lower numbers if the shade is the same or similar?

Also if hair is naturally dark, i. e. black/dark brown, how to get hair to a lighter shade, medium/light brown?

Is is best to go for higher or lower numbers?
And also what shade? Or would you just choose your desired color, i. e. light brown?

But I'm just really confused with the numbers.

[snowangle]

I believe that darker shades have lower numbers, and lighter shades have higher numbers.

If you want to go from a dark brown to a lighter brown, try using a dark blonde dye. But keep in mind that if your hair is already dyed, it's very difficult to get it lighter and you're better off doing it professionally. But you should be able to do it if your hair hasn't been dyed before.

[Lyndsielee666]

To get your hair from dark to light colors you eother have to bleach it or strip ot (if its been dyed) you can't use light colored hai4 dye on dark hair. Kinda common sense.

[Pipsikedee]

Generally (I live in Australia, so maybe its different wherever you live) The lower the number the darker the colour. So black would be a 1 and as the numbers get higher the colour lightens.

[Asker]

I live in the UK so I'm guessing its the same? But what I mean is some colours for e. g. Say Ash Blonde are in low numbers like 6 or 7 and some have the same colour shade i. e. Ash Blonde but are higher number like 73. Are the higher numbers suppose to be used on darker hair and lower on lighter hair?