The Root Problem: Warnings, advice about root touch-up kits

I am not shy about my stance on home hair color.  I have corrected many mishaps from some of the brave and ambitious that take the color bottle into their own hands.   Regardless of the reason anyone colors their hair at home, it will always look better if someone else does it for you.  There are times, unfortunately, where there is no time, or money to go to the salon.  Maybe you have a half inch of gray showing at the temples.  The big event is tomorrow.  What do you do?

This isn't as easy as "pick the color on the box you like and that is exactly how your hair will turn out."  If that was the case, I probably wouldn't have a career as a color specialist.  So here are some things to keep in mind.  

• Consider a temporary option first, like eye shadow or hair mascara.  If it doesn't look like it will be enough, get a root touch up kit.
• Focus on just coloring the roots, specifically at the front hairline and the part.  Don't pull the color through the ends, even if the box suggests it. This color likely has ammonia in it, and your ends already had ammonia on them before.  More ammonia can lead to more damage.
• Study the color of your hair now, and not what it was when the color was fresh, this will make it easier to match shades.  I do not recommend changing your color yourself.
• Understand the tone terms.  Cool tones are also "ice, steel, platinum, ash."  Warm tones include "gold, cream, bronze, copper, auburn, mahogany."  Neutral tones are also "natural, beige."
• If you are just trying to cover gray, buy the box for gray coverage.  
• If you are making your natural color lighter, your hair will likely look more warm than the box.  
• If you are trying to make your natural color lighter, and covering gray, be prepared for variation in color where there is gray versus where there is not.  
• Be neat.  Apply moisturizer on skin around hairline to reduce stains.  Wear gloves.  
• Process color for full time recommended.  Many mistakes are the result of color not processing fully.
• Don't make a habit out of coloring your hairline and part more than once between visits with your colorist.  A good colorist can put you back on track if you made a couple mistakes, but I am a beautician, not a magician.  Also, if you end up needing corrective color, the money and time you saved before might not seem worth it anymore.