Temper Colors?

[baldy]

I've just hardened and tempered a new file razor, but I'm concerned & confused about the color of the steel after tempering.
The blade was in the toaster oven for 2 x 1 hour cycles at around 395-400 F.
I was expecting a straw/yellow color, but there is definitely shades of blue/purple in there.
It never went over 400F during the tempering. It is however an unknown steel.
It was an old Wilthshire file.
Can anybody shed any light on the coulors here, have I over cooked it?







Thanks
Grant