Once you’re past 30, you want to set aside the makeup law says that your foundation always has to closely match your natural complexion. The thing is, skin becomes paler as you age. It's something you need to disguise. You need more color there. What you're looking for then is a slightly darker shade than your skin is.
At some point in your 30s, you're going to start to need concealer. The only problem is that concealer can sometimes actually make your lines stand out. Using it could turn into a bad make up habit. Instead of staying above your lines and concealing them, it'll sink into them and harden their edges. To keep this from happening, make sure that you only use concealer for certain parts of the face.