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.
Hair color ideas are not stand alone thoughts and need to be combined with your skin tone and personality to give you the right match. Never copy someone else's hair color idea blindly as it just might be completely wrong for you. If you are coloring your hair for the first time, you can seek professional help at the salon. Otherwise, the internet is a good place to start with as well: