How to tip a famous colorist ?URGENT HELP

Hi all ,

I have been reading this forum for a while now and it always answered all my questions without me needing to post .

I even found out here that Rita Hazan in NYC was the key to my blonde problems ...

So after reading all about her here i have decided to go there to better my already blonde mane ... so I am going in 3 days ( I am soooo excited to meet her and to see what she can do with my hair )

but here is the big question: Rita Owns her salon and as all of you guys probably know my bill is probably going to be around $500 -Also she colors J.Lo , Celine Dion and Jessica Simpson's hair .

NOW : Do i have to tip her ( I am assuming all $500 will go to her since she is the owner ) but I would feel weird not tipping .

1/ Am I supposed to tip her although she is the owner of the salon and charges hefty fees ?

2/ if i do have to tip her what is a decent tip for a colorist in her category? ( I certainly cant tip her $40 thats for sure ...)

Please help I am due to go there in 2 days and i am soooo clueless

Thanks