BEAUTY TIP 101
While it is certainly easier and faster to swipe some foundation on your inner arm to see if it matches your skin tone at the store, it will almost never be an accurate match. It is most likely that the colour of your arm does not match the colour of your face.
To avoid purchasing the wrong shade and wasting money in the process, rather go the extra mile before you purchase anything to be sure you have the correct shade for your complexion.
Always do the colour test on your jawline and blend it down into your neck, not on your arm or hand. The colour of the foundation should fade in naturally into your neck. You should not be able to see where the foundation ends and where your skin tone begins. Then you know that you have found the correct match.