Hair coloring is safe, because I have tried it at home using one of those kits. My hair is still nice, thick and silky as it was before. There are many myths in India about hair coloring and its bad effects.
In India, many women are going for light brown or blonde highlights. Most Indian women have dark black hair, which is would be about no. 2 or 3. In the hair color grading system, no. 1 is the darkest (black) and no. 10 is the lightest (light blonde). Inidan type hair is difficult to color because our hair is really healthy and the cuticles are really strong. This is because we oil and take good care of our hair right from childhood, use less heat for ironing, blow-drying or curling and use less color and other styling gels(which contain harsh chemicals). So to color such strong hair from no. 2 to a lighter color, most beauty parlors in India use bleach (which contains ammonia), which first lightens the hair color, and then apply the color on top of it. Bleaching damages the hair.
Once you color or highlight your hair, it will last for a long time, provided you take good care with color protection shampoo/conditioner. So don't worry; coloring is something you do just once in a while. Go ahead and be bold, girl. Experiment with your looks.
Good luck!!