Adjustment Layers Default Colours

When I create a Color Balance adjustment layer to colourise a selected area the Default Foreground & Background colours switch from Black/White to White/Black automatically with even the icon in the corner changing to reflect this (When switching manually back to Black Foreground the icon stays showing White as Foreground). By switching manually back I can refine Masks as I have been doing for sometime with the Eraser deleting parts of a mask and the Paintbrush adding to the size of the mask which is the logical way It seems like I have somehow changed the default Foreground/Background when applied to Adjustment Layers as I just tried using a Curves etc Adjustment Layers with the same thing happening with the defaults changing to White foreground etc automatically. Is there something I have ticked or changed that has made this change

You're not experiencing anything unusual. When you create a mask layer the entire mask is initially white (unless you make a selection before applying the mask/adjustment layer), so Photoshop automatically puts white in the foreground and black in the background. That little icon in the corner is doing its job, allowing you to return your foreground/background colors to the default. In any case I don't see this as being a big problem, right? If you're worried that you broke something relax. All is as it should be!

Thanks again but... The defaults auto change to W/B even with a selection applied in my case, and this change occurred without warning after a return to some colourising projects I had already been working on with B/W Fore/Back colours as selection masks were applied and the Eraser (Delete mask) Paintbrush (Add mask) worked when refining masks. What I mean is that up until the last few weeks my default mask colours must have been B/W and somehow changed to W/B requiring the manual switch to edit masks using the eraser deletes/brush adds. As you say it doesn't cause that much of a problem but still I would really like to know how this changed has occurred as it seems to be a default unchangable sort of thing.
Sorry to go on about this but as a basic computer user, these sort of unexplainable thing freaks me out a bit!

Well I can see where you're coming from with wanting to know why it's doing that. I tried to get PS to do what you're describing and it wouldn't replicate your results. I also couldn't find any way to manually switch this setting. Might be an installation thing, but don’t take my word for that. If you had any pictures to make sure I'm looking at the right part of the interface then... but it's probably not worth the trouble. *shrugs*