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.
Medium Brown: For Light Beige or Beige scalp tones.
Light Brown: For Light Brown scalp tones.
Dark Brown: For Dark Brown scalp tones.