Color Dark Brown Hair
A: Yes. Of course it is. You simply need to pre-lighten the hair to a level that is lighter than the caramel brown color, unless the target color is within 3 shades lighter than the original color.
In some cases, depending on the base color of your natural hair, simply lightening the hair will give you the desired color (or very close to it). Otherwise, lightening and coloring, or color-lightening the hair will give you the lightness and tone you want for the desired color.
A couple of cautions, however: don't try lightening the hair too far. If the color you want to have is more than 4 shades lighter than your original color, go for an intermediate color first and let the hair recover.
Hair coloring, particularly lightening, can be harsh to the hair, and you need to avoid do anything too drastic so as to prevent damaging the hair. Give the hair a few weeks of regular conditioning to get rehydrated and back into good condition before continuing to lighten to the desired color.
Also, be careful to make sure that the base color of your desired hair color is compatible with the base color of your natural color (or starting color). If you don't, you can end up with unfortunate effects. Like taking an original color with a reddish base tone, lightening it and adding a lighter hair color that has an orange base, could result in an orange-ish tint to the finished color, especially if you over-lighten the hair.
©hairfinder.com
See also:
How to color hair
How bleaching works
Hair color levels and peroxide developer
Lighten hair color without bleaching