The Masthead is a key feature which differentiates magazines from each other - some magazines stick to the same colour scheme (e.g Billboard and Rolling Stone), while others change in order to fit the colour scheme (e.g Vogue).
Most of the Rolling Stone issues have the musician/actor/politician covering the title and this is understandable because they have been around for quite a long time, dating back to the late 1960s. Similarly, Vogue too has made a name for themselves, however, they seem to play it safe and it changes depending on what looks nicer.
I also noticed that certain artists such as M.I.A don't get to cover up the title of Billboard because they're not as big as the likes of Rihanna - the magazine is more known than them.
NME has two different colours it normally goes for: red and white. This then shows consistency throughout the issues.