The complete Longyear Diamond Bit Series includes different colors, with each one corresponding to specific hardness ratings found on the standard Mohs hardness scale.
In order to work properly, every bit is designed to run with a given amount of down pressure. It takes a certain amount of push. When drilling vertically, this is bit weight.
I always approach a project with this goal in mind: To drill an efficient borehole safely utilizing the tooling and equipment on site with the least amount of impact to the environment.