I see reddish coloration, but not brown.  However, the leaves and buds in two of the photos are out of focus, so perhaps I'm missing something there; if that is the case, please re-take those photos and send to <personal data hidden>.  In the third photo, the reddish color may be characteristic of new leaves on that particular variety of apple.  Have you seen the new leaves on this tree in past years, and if so, do you recall whether they did or did not have a reddish coloration?  Weather may also impact the severity of the reddish coloration.  Cool temperatures often result in a reddish coloration which is related to phosphorus deficiency in the leaves, but it is highly unlikely the overall plant is deficient in phosphorus, and the leaves likely will lose the red color in the near future.