How long will a semi permanent hair colour last and what's the difference between that and permanent?

semi permanent color last up to 5 to 6 shampoos,and the permanent stays on till your hair grows back to your natural color, permanent has peroxide and semi permanent dosent.How long will a semi permanent hair colour last and what's the difference between that and permanent?
Semi-permanent lasts on average about 6 weeks...and is a lot easier on your hair than the permanent longer lasting colour. Plus which, the colours themselves seem a lot more natural...not as stark, and do not shriek ';dye-job!';. Clairol products seem the best and most gentle for repetitive use... I've known people who have used the same semi-permanent colouring every six weeks for YEARS with no ill effects to hair texture, strength or shine.How long will a semi permanent hair colour last and what's the difference between that and permanent?
There are 3 kinds of hair dye. Semi-permanent only lasts about a week, demi-permanent which will last a month or so and then slowly fade, and permanent. The difference is that non permanent dyes don't have as many chemicals in them, and can't lighten your hair very much. They work great though if you want to go darker, and you don't have to worry about roots.