L., I would not recommend going to Sallee Beauty Supply. Although the process and solutions are the same in an OTC product and at the salon, the products are sold separately (color, developer, etc.) at the beauty supply store and, if you don't know what you are doing, you can ruin your hair. It can be a complex process and you had better know what you are doing before you get into... no quick and easy instructions for this one. Once you get used to doing your hair yourself, you may find that you prefer to go to the beauty supply house for your chemicals. This way, you can mix and blend to create the hair color you want and that is unique and complimentary to your skin tones.
You asked for something simple and quick and most of the responders offered several practical solutions. Despite what the adds on tv tell you, most hair colorants of the same class are basically the same, regardless of the price. The pivotal factor is how it reacts with your hair.
There are three types of hair colorants:
1) The rinse or spray-in group are good until you wash your hair the next time. These are not intended for long-term hair color change or grey control.
2) The temporary/semi-permanent hair color. These will last for six to ten washings, gradually getting lighter with each shampooing until it has pretty much faded completely.
3)Permanent hair colors. These will fade gradually but will not complete wash out and, thus, will leave that tell-tale root line.
I would suggest starting with a temporary hair color if only to get used to doing it yourself. You may even find that you prefer this method to any permanent hair color solution.
As far as price = better quality, this is not necessarily so. But someone mentioned Perfect 10. This is probably the fastest permanent hair color available - ten minutes - hence the product's name. Most of them take 20 - 30 minutes not counting rinsing/washing it out. It is also, however, the most expensive of the hair colors available over the counter. You are paying more for the faster processing. Most hair coloring products are going to run you between $6.00 and $15.00 with a few running a little higher. All temporary and permanent products come with latex gloves and simple step-by-step instructions. Millions of women (and men) use it every day.
A few caveats, if you will. The hair coloring will stain or bleach color out of fabrics and can stain porous walls and floors as well so be careful when applying any product to your hair. Permanent hair coloring can also stain your skin. Sea Breeze astringent/cleanser is recommended to wipe any smudge that may have gotten on your skin, especially if you are using a darker color! If you find a hair coloring product is not suitable for your hair, that does not mean they all are bad. As I said, they are all basically the same regardless of whether you do it yourself or let a beautician do it for you. Just like shampoos, some of them just are not compatible with your hair type. Switch to another brand and see if that's gentler on your hair.
You can spend $2,000 each year at a salon to get your hair colored, or $200 to do it yourself. The results, as someone already reported, are about identical. And while the difference in appearance may be negligible, the difference in your wallet is anything but. You could practically plan a family vacation on that savings alone!
Good luck.