Without much fanfare, Apple today released a small hardware refresh of its MacBook 12" and MacBook Air notebooks.The refreshed MacBook now sports sixth-generation Intel Core M, which can be configured with either 1.1GHz or 1.3GHz clock speed. The RAM is also upgraded from 1600MHz to the faster 1866MHz and the Intel HD 515 GPU promises 25% better efficiency. And, yes, there's a new rose gold color