Hello MM!.
So I am taking up a job that involves by hair being died crazy colors such as purple, blue, red, orange and bleach blonde also. I have very thin hair dirty blonde hair. If I were to have it died these crazy colors with a high end brand, how quickly would it come out. I would like it out in a matter or 3 weeks 4 weeks tops. So from what I know from hair, I either have the option of getting it out of getting some out and re dying my hair dirty blonde again, correct?. I have died my hair about 3 years ago black and blonde (I looked like a skunk). Other people with thin hair dye it right?. How might this effect me?.

Hillaire an agency booker would most likely never ever send one of their talents out on any assignment that involves either cut and/or color... A model's hair is her most important fashion accessory... the longer the better, in as it allows hair stylist the maximum latitude in achieving a visual statement for a given narrative...

Best advice? walk away from this gig... so many naive talent have rue the day they allowed their tresses to be cut and/or colored...

btw, I collaborate frequently with a top hairstylist who is also a colorist... in fact she did my best friends highlights... her wisdom is that you NEVER know how a product will work until you do test strips on a small section that does not show... Tenured colorist know this and will always do test strips... even then they typically mention that the end results may or may not be close and they can't assure exactly how it will come out since contact time with the product is highly variable... 

seriously rethink this gig...

Actually there are a ton of "HAIR JOBS" that require models to cut and color their hair. So they do exist and models are sent out to them.

However if this color isn't going to come out quickly and prevent you from having other jobs, I would have to seriously rethink it.

I see both points. I am not worried about other jobs, just getting it out if needed. I do appreciate each of your feedback.