Hello Everyone !

I want a new keyboard and I'm looking for a mechanical one. I need suggestion because I hesitate between Corsair K70, Logitech G710 or the Razer BlackWidow. What do you think ? My budget is approx. 150$CAD (approx: 120 USD). And If someone can explain me because I really don't understand exactly what is the difference between Cherry Blue, Brown, Green and Red.