Assessing the Damage

• First and foremost, evaluate your hair color. What exactly don't you like about it and what do you need to do in order to change it? The key to correcting hair-color mistakes is to understand the nature of the job in order to employ the proper solution.
  
  As with any color correction you undergo, it is important to understand that if you used a permanent dye during the first round of hair coloring, using another permanent color immediately following your mistake can possibly leave you with over-processed, dry and brittle hair.
  
  

A Safe Alternative to Hair Color Correction

• A safer and highly effective method of hair-color correction is to use a semi or demi-permanent hair color as opposed to a permanent. Semi and demi-permanent colors are tamer coloring agents that coat your hair's shaft as opposed to penetrating the strand (as is the case with permanent dyes).
  
  Semi and demi-permanent colors attach to your hair's current color and reflect a color that is more suitable to your taste without damaging your hair. Unlike permanent hair color, these forms of hair coloring tend to wash away after 10-20 shampoos; however, they leave behind a subtle hint of color which helps mask your previous color mistake.
  
  

Proper Color Correction Techniques

• If you are looking to tone down your current color, use a color on the opposite end of the color wheel. For instance, if you made a fire-engine red color mistake, a color such as a warm brown will help tone things down. If, on the hand, your color is too dark or has become too brassy over time, consider choosing a semi or demi-permanent shade that is at least two shades lighter than your current color. Semi and demi-permanent colors do not lighten hair; they only deposit color. Be sure to choose a color that will show up on your hair, as this form of coloring will wear off over time.