Cobalt blue creeping in on my pictures

Working with RAW files I have noticed that a Cobalt blue color has begun to take over the black areas in my pix when working it the raw editor in PE19. I saw a reference to this phenom in the forums from 5 years ago that suggested right mouse on the blue are and select black from a popup. Right mouse only brings up the options for the view ratio. %%

Why is the blue there in the first place and how do I get it back to black

Thanks!!