Weird reaction with my Konosuke?

I have the HD gyuto and i don't really have any reactions to any foods with it.

although we got this new wheel of cheese in, its a creamy gorgonzola and my knife along the edge has what looks like the cheese stuck to it.

However its not i have washed it completely and tried to scrub it off and it on the metal itself, its almost white- yellowish looking.

Also don the heel about the edge it has turn a bright yellow in streaks, this came off when i rubbed it down with some oil.

Anyone else experience this at all?

i have never heard of or seen such a thing, and I did use the HD to divvy up some brie the other day (it was already out cutting other foods). a pic or two available?

patina or other corrosion.