Color & highlights to solid color

Hello! I've decided to change my present color, which is medium brown with golden blonde highlights to a solid medium auburn color - sort a cross between Lindsay Lohan & Nikki Cox's hair colors. My natural color is very dark brown.

Will this be an involved process for my colorist to achieve, given the highlights I presently have?

My hair is a little on the dry side, but not too damaged. I was hoping that she could achieve this color with a demi-permanent dye. Do you think that will work?

Thanks!

I think that a demi would work fine, but your highlights might peek through a bit, which would actually look nice, in my opinon. Afterward, if you use a color-enhancing shampoo, such as Artec in Cherry Bark, that should help a lot with the fading factor. I hope you get what you want. Good luck!