I absolutely love the "two tone" look! Thanks so much for the picture. :D
Nice job on the polishing, too!

-A knife loving fox

The two tone colouring is a by product of the forging, quenching and tempering.
When I quench the 52100 steel while it's a bright red colour in the oil, most of the darker blackish grey scale pops off and reveals a silky light grey colour.

The bevel of the knife was polished to a flat grey colour so it was easier to see the temper colours creep from the spine of the knife down to the edge. Tempering colours range from a light stray to a dark brown, a purple, peacock blue, etc.

Since I heated up the jaws of a pair of tongs and held it against the spine of the knife, that decreased the hardness near the spine more than the edge.

The polishing job is alright, it's also a byproduct, but from sharpening. I use a norton abrasives combination stone and the polish came from the stropping.