When you use the services of a real professional, go to the appointment with an open mind. You may have your heart set of pale blond, but if the colorist can prove to you that a deep strawberry is really your best shade, listen to her. She is trained to match color with skin tone. She knows what will work, and what won't.
Hair color isn't always about just "color". It's about shades, hues, and a good cut that will show off your new color. Perfect color doesn't come in a bottle. If you are hoping to get a color correction for past mistakes (caused either by you or another salon), it will take a real expert to add in the right toners to counter the faulty shades you are trying to get rid of.