Permanent Dye Over Semi-Permanent?

I dyed my hair with a semi permanent dye a couple of weeks ago and I love the colour and want to dye it permanently before it fades too much and goes back to my natural colour. Do I have to wait until it's all been washed out to dye over it permanently or can I do it now? (as it is the same color, not lighter)

I am going out in a week or so and want my hair to stay the present color, instead of looking faded. :)

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You have two choices. Use another application of the semi permanent color so you're hair color will look refreshed, or go ahead and try a permanent hair color.

The problem is, that most box colors (which I must assume you're using) typically come with 20 volume peroxide, especially brown or red colors. Since 20 volume peroxide can lift your hair, the hair color you get might not match your present color.

To keep your hair color rich, use a 10 volume peroxide instead of a 20 volume peroxide.

To get a 10 volume peroxide, mix the 20 volume peroxide 1:1 with purified water but only use half the mix when you color your hair. For example, if the box has 4 ounces of peroxide, you'll only need 4 ounces to mix with your color. If you mix the 20 volume 1:1 with water, you'll have 8 ounces. Only use 4 of the 8 and dispose of the leftovers.

It might look darker at first but it will fade a bit over time. If you are unsure of the results you'll get, do a strand test first.

Also, if the box color does not tell you which volume of peroxide's in it, there should be a 1-800 number to call. Ask first, before you color.

Make sense?