It mainly features a gradient of a soft magenta to an extremely soft yellow. These colours give an impression that the weapon blade has been recently been heated by a furnace. As no-one really wants to touch a blade of high temperature, the name is appropriate as it can look like it can significantly harm.
Fierce for the Rambo Knife can be found in the Free Model catalogue within ROBLOX.
The Fierce for the Karambit is a reference to CS:GO's Fade skin.