1. Use a primer. A silicone-based primer acts as a barrier between your skin's natural oils and oils in foundation, so there's less chance of oxidation.
2. Blot, and blot some more. 
3. Try a sheerer formula. 
4. Use a finishing powder.

The term “oxidized foundation” to describe a foundation that changes color during wear, but true oxidation actually doesn't occur that quickly. However, oxidation can occur in the bottle over the long term (about 6 months to a year after opening).

There are many contributing factors that may cause your foundation to oxidize, skin texture, cleanliness, natural oils, and even the way a foundation appears once it is applied, dries, and is mixed with oxygen. Luckily, there are things you can do to prevent this. 

This may seem like a no brainer, but clean skin is healthy skin, and healthy skin is happy skin. Don't even think about applying foundation on an unwashed face (or worse — over yesterday's makeup!) That's just asking for mismatched tones and a host of other problems, too. Be sure to cleanse your face each morning, prior to applying any product or makeup.

the battle really begins with the foundation itself, and finding the right foundation for you is key.  not all foundations oxidize and it's really a matter of trial and error to find the right one for you and your skin in the first place.if you fall in love with a brand that oxidizes, you’d want to get that foundation in a shade lighter than what you would normally wear. This will help to balance the color change and make sure you're well matched.