Choosing an Eyebrow Color

• The best thing to do is to go by the color of the hairs in the eyebrow area. 
• Choose a color that is a couple of shades lighter than those hairs. It makes for a natural undetectable look.
• If your client has no hair in the brow area, choose a color that she likes and looks natural with her skin type. 
• You can create different variations of the same color according to how many times you pass over the same area. 
•  The more times you pass over the same area, the darker the color will appear and the closer get to the color in the bottle.

Remember that 

• The beginning of the brow should be the lightest part, the arch area is the darkest part of the brow, and the tail or the descending part of the brow should be in the middle. 
• In order to simulate this effect, pass over the front of the brow the least amount of times, the tail – slightly more times, and the arch the most times. 
• Keep in mind that to leave the brow looking extremely natural looking, don't put a definite/harsh shape in the front of the brow, this makes an eyebrow look totally artificial.

You must know that

• A full natural eyebrow fades from the skin into short small diameter hairs in the bulb area that are approximately .002" (2 one thousandths of an inch in diameter). 
• The hairs then gradually become larger in diameter toward the arch – approximately .003"-.004" in diameter, and keep their thickness but are less concentrated in the tail area. 
• To simulate this effect, you will need to pass over the same area less times to simulate finer diameter hairs and more times for the larger diameter hairs