You want to match the lace color with your scalp complexion not your skin tone. This is because when you part the unit, you want it to appear as your natural scalp color. So to check your scalp color part your hair and look at the color of your scalp to determine your lace color.
Transparent:
For White, Off White or Cream scalp tones.
Light Brown:
For Light Brown or beige scalp tones. Choose this if you want your scalp to have a light brown tint.
Lace Color