Onyx is one of the first manufacturers to install e-ink color screens. And with the Boox Nova Air C model, the company could become one of the most important players on the market of digital color readers. You can upload any text e-book, magazine or comic here, and the tablet can handle it. Moreover, the competition is not able to offer similar equipment, such as a color screen or a stylus. However, is there any “but” …?