How long does Revlon Colorsilk last?

My hair is dark brown and I got the Revlon Colorsilk Auburn brown (49) Permanent. How long will it last for?How long does Revlon Colorsilk last?
I have use it before and it last very long like 3 months really I and not kidding .I think revlon is a great products I have use more expensive but I can say this products is cheap and it really works well.How long does Revlon Colorsilk last?
I only use their makeup but I have used the other hair color products and it will depend on how often you wash your hair and what condition it is in. Most permanent hair color will stay in until you cut it out but it tends to fade if you don't use the shampoo for Color treated hair or you wash it to often.
I don't know how long it will last, but I will be honest and say that Revlon is not a good brand for hair dye. I would go with L'Oreal. I don't dye my hair personally, but I have a cousin who changes her color every 3 months and she's also a hair stylist/works at a salon. Revlon is great when it comes to makeup, but their hair products are not worth it. Next time buy Clairol or L'Oreal.
Usually 4 to 6 weeks, it will fade if you are in the sun alot and also if you wash your hair very often! Hope I've helped! Good Luck!!!!!!!!